Charging control apparatus and charging control method for use in mobile devices and charging system

ABSTRACT

A charging control apparatus provides a supply power to first and second mobile devices. Each of the first and the second mobile device includes a mobile charging circuit and a battery. The charging control apparatus includes a switching power converter for converting an input power to the supply power, and a conversion control circuit for controlling the switching power converter according to the following steps: S1: controlling the switching power converter, so as to establish a current versus voltage characteristic curve corresponding to the supply power; and S2: determining a charging mode combinations of the first and the second mobile device and/or adjusting a supply voltage of the supply power to charge the battery of each mobile device according to the current versus voltage characteristic curve, so as to reduce a voltage drop of each mobile device as well as the power loss.

CROSS REFERENCE

The present invention claims priority to TW 109141165 filed on Nov. 24,2020.

BACKGROUND OF THE INVENTION Field of Invention

The present invention relates to a charging control apparatus;particularly, it relates to such charging control apparatus for use inmobile devices. The present invention also relates to a charging controlmethod for use in the mobile devices. Besides, the present inventionrelates to a charging system including such charging control apparatusand such mobile devices.

Description of Related Art

Please refer to FIG. 1, which shows a schematic block diagram of aconventional charging control apparatus (i.e., charging controlapparatus 101) for use in a mobile device. The conventional chargingcontrol apparatus 101 can be for example a charging box. The mobiledevices 30[1] and 30[2] can be for example a true wireless stereo (TWS)headphone. The conventional charging control apparatus 101 includes: abattery 11, a state of charge meter circuit 12, a microcontroller 13, abuck-boost power converter 14′. Each of the mobile devices 30[1] and30[2] includes: a mobile charging circuit 31 and a battery 32. Thebuck-boost power converter 14′ is configured to operably convert abattery power supplied from the battery 11 to a supply voltage VS. Eachmobile charging circuit 31 of the corresponding TWS headphone (i.e.,mobile devices 30[1] and 30[2]) can subsequently convert the supplyvoltage VS to a corresponding charging power VC, to charge thecorresponding battery 32. Because the batteries 32 of the TWS headphones(i.e., mobile devices 30[1] and 30[2]) may have different chargequantities, the conventional charging box (i.e., charging controlapparatus 101) employs a power line communication (PLC) module 15 tocommunicate with the PLC module 33 of each TWS headphone (i.e., mobiledevices 30[1] and 30[2]) by means of power line communication (PLC), soas to obtain information concerning battery capacity, voltage or currentof the TWS headphones (i.e., mobile devices 30[1] and 30[2]), andadjusts the supply voltage VS generate from the buck-boost powerconverter 14′ accordingly, so as to reduce a voltage drop of the mobilecharging circuit 31 of each corresponding TWS headphone (i.e., mobiledevices 30[1] and 30[2]), thus enhancing power conversion efficiency andreducing heat generation, thereby improving durability of the h battery32 in the conventional charging box (i.e., charging control apparatus101).

The prior art charging box (i.e., charging control apparatus 101) shownin FIG. 1 has the following drawbacks that: because it is required forboth the charging box (i.e., charging control apparatus 101) and the TWSheadphones (i.e., mobile devices 30[1] and 30[2]) to employ a PLC module(e.g., PLC module 15 and PLC modules 33), the prior art charging controlapparatus 101 requires a larger space, has a higher cost and consumesmore power.

As compared to the prior art in FIG. 1, the present invention isadvantageous in that: it is not required for the charging controlapparatus of the present invention to adopt a PLC module, which canresult in saving space and size reduction of the charging controlapparatus and the mobile devices; the cost and power consumption arealso reduced.

SUMMARY OF THE INVENTION

From one perspective, the present invention provides a charging controlapparatus, which is configured to operably provide a supply power to atleast a first mobile device and a second mobile device, wherein each ofthe first and the second mobile device includes: a mobile chargingcircuit and a first battery, wherein each mobile charging circuit isconfigured to operably convert the supply power to a charging power forcharging the corresponding first battery, wherein the mobile chargingcircuit is operable in at least two of the following charging modes: aprecharging (PC) mode, a constant current (CC) charging mode and aconstant voltage (CV) charging mode, so as to charge the correspondingfirst battery; the charging control apparatus comprising: a switchingpower converter, which is configured to operably convert an input powerto the supply power, wherein the supply power has a supply voltage and asupply current; and a conversion control circuit, which is configured tooperably control the switching power converter; wherein the conversioncontrol circuit is configured to operably control the switching powerconverter according to the following steps: step S1: controlling theswitching power converter to gradually adjust a level of the supplyvoltage within a preset voltage range and sense a level of thecorresponding supply current through, or, to gradually adjust the levelof the supply current within a preset current range and sense the levelof the corresponding supply voltage, thereby establishing a currentversus voltage characteristic curve corresponding to the supply power;and step S2: performing one of the following step S21 or S22 accordingto whether the current versus voltage characteristic curve has at leastone mode inflection point and according to information indicated by thesupply current and/or the supply voltage corresponding to the at leastone mode inflection point in a situation where the at least one modeinflection point is present: step S21: determining a charging modecombination where the first mobile device and the second mobile deviceare in; or step S22: in the situation where the at least one modeinflection point is present, adjusting the supply voltage according tothe information indicated by the supply current and/or the supplyvoltage corresponding to the at least one mode inflection point, so asto charge the first battery of the corresponding mobile device accordingto the supply voltage, such that a voltage drop of each mobile chargingcircuit is reduced.

In one embodiment, the step S21 includes: in the situation where the atleast one mode inflection point is present, comparing the informationindicated by the supply current corresponding to the at least one modeinflection point with a preset precharging (PC) current level and apreset constant current (CC) current level, so as to determine thecharging mode combination where the first mobile device and the secondmobile device are in.

In one embodiment, the step S21 includes: comparing the informationindicated by the supply voltage corresponding to the at least one modeinflection point of the current versus voltage characteristic curve witha constant voltage (CV) voltage threshold and a CC voltage threshold, soas to determine the charging mode combination where the first mobiledevice and the second mobile device are in.

In one embodiment, in the step S21, the conversion control circuit isconfigured to operably determine which charging mode combination thefirst mobile device and the second mobile device are in according to thecurrent versus voltage characteristic curve by at least one of followingsteps:

step S210: in a case wherein the current versus voltage characteristiccurve has no mode inflection point, or, in a case wherein within thepreset voltage range, the corresponding levels of the supply current areall lower than the preset PC current level, determining that the firstmobile device and the second mobile device are in a charging modecombination (0), wherein in the charging mode combination (0), the firstmobile device and the second mobile device are both in a chargingtermination mode;

step S211: in a case wherein the current versus voltage characteristiccurve has one and only one mode inflection point and in a case whereinafter the supply voltage has exceeded the mode inflection point, thecorresponding level of the supply current is equal to the preset PCcurrent level, determining that the first mobile device and the secondmobile device are in a charging mode combination (1), wherein in thecharging mode combination (1), one of the first mobile device and thesecond mobile device is in the PC mode, whereas, another one of thefirst mobile device and the second mobile device is in the chargingtermination mode;

step S212: in a case wherein the current versus voltage characteristiccurve has one and only one mode inflection point and in a case whereinafter the supply voltage has exceeded the mode inflection point, thecorresponding level of the supply current is greater than the preset PCcurrent level and smaller than the preset CC current level, determiningthat the first mobile device and the second mobile device are in acharging mode combination (2), wherein in the charging mode combination(2), one of the first mobile device and the second mobile device is inthe CV charging mode, whereas, another one of the first mobile deviceand the second mobile device is in the charging termination mode;

step S213: in a case wherein the current versus voltage characteristiccurve has one and only one mode inflection point and in a case whereinafter the supply voltage has exceeded the mode inflection point, thecorresponding level of the supply current is equal to the preset CCcurrent level, determining that the first mobile device and the secondmobile device are in a charging mode combination (3), wherein in thecharging mode combination (3), one of the first mobile device and thesecond mobile device is in the CC charging mode, whereas, another one ofthe first mobile device and the second mobile device is in the chargingtermination mode;

step S214: in a case wherein the current versus voltage characteristiccurve has at least one mode inflection point and in a case wherein thecorresponding level of the supply current which corresponds to agreatest one of the supply voltages corresponding to the at least onemode inflection point is equal to two-fold of the preset PC currentlevel, determining that the first mobile device and the second mobiledevice are in a charging mode combination (4), wherein in the chargingmode combination (4), the first mobile device and the second mobiledevice are both in the PC mode;

step S215: in a case wherein the current versus voltage characteristiccurve has a plurality of inflection points and in a case wherein thecorresponding level of the supply current which corresponds to thegreatest one of the supply voltages corresponding to the at least onemode inflection point is greater than two-fold of the preset PC currentlevel and smaller than a sum of the preset CC current level plus thepreset PC current level, determining that the first mobile device andthe second mobile device are in a charging mode combination (5), whereinin the charging mode combination (5), one of the first mobile device andthe second mobile device is in the CV charging mode, whereas, anotherone of the first mobile device and the second mobile device is in the PCmode;

step S216: in a case wherein the current versus voltage characteristiccurve has the at least one mode inflection point and in a case whereinthe corresponding level of the supply current which corresponds to thegreatest one of the supply voltages corresponding to the at least onemode inflection point is greater than two-fold of the preset PC currentlevel and smaller than two-fold of the preset CC current level,determining that the first mobile device and the second mobile deviceare in a charging mode combination (6), wherein in the charging modecombination (6), the first mobile device and the second mobile deviceare both in the CV charging mode;

step S217: in a case wherein the current versus voltage characteristiccurve has the at least one mode inflection point and in a case whereinthe corresponding level of the supply current which corresponds to thegreatest one of the supply voltages corresponding to the at least onemode inflection point is equal to the sum of the preset CC current levelplus the preset PC current level, determining that the first mobiledevice and the second mobile device are in a charging mode combination(7), wherein in the charging mode combination (7), one of the firstmobile device and the second mobile device is in the CC charging mode,whereas, another one of the first mobile device and the second mobiledevice is in the PC mode;

step S218: in a case wherein the current versus voltage characteristiccurve has the at least one mode inflection point and in a case whereinthe corresponding level of the supply current which corresponds to thegreatest one of the supply voltages corresponding to the at least onemode inflection point is greater than the sum of the preset CC currentlevel plus the preset PC current level and smaller than two-fold of thepreset CC current level, determining that the first mobile device andthe second mobile device are in a charging mode combination (8), whereinin the charging mode combination (8), one of the first mobile device andthe second mobile device is in the CC charging mode, whereas, anotherone of the first mobile device and the second mobile device is in the CVcharging mode; and/or

step S219: in a case wherein the current versus voltage characteristiccurve has the at least one mode inflection point and in a case whereinthe corresponding level of the supply current which corresponds to thegreatest one of the supply voltages corresponding to the at least onemode inflection point is equal to two-fold of the preset CC currentlevel, determining that the first mobile device and the second mobiledevice are in a charging mode combination (9), wherein in the chargingmode combination (9), the first mobile device and the second mobiledevice are both in the CC charging mode.

In one embodiment, in a case wherein the charging control apparatus isconfigured to operably determine the charging mode combination where thefirst mobile device and the second mobile device are in according to atleast one of the step S212, the step S215, the step S216 or the stepS218, each of the step S212, the step S215, the step S216 and the stepS218 further includes a corresponding operation as the following:

the step S212 further including: only when the information indicated bythe supply voltage corresponding to the at least one mode inflectionpoint is greater than or equal to the CV voltage threshold, thendetermining that the first mobile device and the second mobile deviceare in the charging mode combination (2);

the step S215 further including: only when the information indicated bythe greatest one of the supply voltages corresponding to the modeinflection points is greater than or equal to the CV voltage thresholdand when the information indicated by the smallest one of the supplyvoltages corresponding to the mode inflection points is smaller than theCC voltage threshold, then determining that the first mobile device andthe second mobile device are in the charging mode combination (5);

the step S216 further including: only when the information indicated bythe supply voltages corresponding to the at least one mode inflectionpoint are all greater than or equal to the CV voltage threshold, thendetermining that the first mobile device and the second mobile deviceare in the charging mode combination (6); and/or

the step S218 further including: only when the information indicated bythe greatest one of the supply voltages corresponding to the at leastone mode inflection point is greater than the CV voltage threshold andwhen the information indicated by the smallest one of the supplyvoltages corresponding to the at least one mode inflection point issmaller than the CV voltage threshold and is greater than or equal tothe CC voltage threshold, then determining that the first mobile deviceand the second mobile device are in the charging mode combination (8).

In one embodiment, in a case wherein the step S21 is present, theconversion control circuit is configured to operably control theswitching power converter further according to the following step: stepS3: according to the charging mode combination where the first mobiledevice and the second mobile device are in and according to theinformation indicated by the supply current and/or the supply voltagecorresponding to the at least one mode inflection point, adjusting thesupply voltage to charge the first battery of the corresponding mobiledevice, so as to reduce the voltage drop of each mobile chargingcircuit.

In one embodiment, the step S3 includes the following step: step S31: ina case wherein the first mobile device and the second mobile device arein the charging mode combination (1), the charging mode combination (2)or the charging mode combination (3), according to the supply voltagecorresponding to the one and the only one mode inflection point,determining the level of the supply voltage to charge the first batteryof the corresponding mobile device, so as to enhance charging speed andreduce the voltage drop of each mobile charging circuit.

In one embodiment, wherein the step S3 includes one of the followingsteps: step S32: in a case wherein the first mobile device and thesecond mobile device are in the charging mode combination (4) to (9), ina power-saving power supply mode, according to the smallest one of thesupply voltages corresponding to the at least one mode inflection point,determining the level of the supply voltage to charge the first batteryof the corresponding mobile device, thus reducing the voltage drop ofeach mobile charging circuit; step S33: in a case wherein the firstmobile device and the second mobile device are in the charging modecombination (4) to (9), in a fast-charging power supply mode, accordingto the greatest one of the supply voltages corresponding to the at leastone mode inflection point, determining the level of the supply voltage,so as to charge the first battery of the corresponding mobile device,thus enhancing charging speed and reducing the voltage drop of eachmobile charging circuit; or step S34: in a case wherein the first mobiledevice and the second mobile device are in the charging mode combination(4) to (9), in a balance power supply mode, adjusting the level of thesupply voltage, so that the adjusted level of the supply voltage liesbetween the greatest one of the supply voltages corresponding to the atleast one mode inflection point and the smallest one of the supplyvoltages corresponding to the at least one mode inflection point, thuscharging the first battery of the corresponding mobile device, therebybalancing charging speed and power loss.

In one embodiment, the step S22 includes one of the following steps:step S221: in a power-saving power supply mode, determining the level ofthe supply voltage according to the smallest one of the supply voltagescorresponding to the at least one mode inflection point, so as to chargethe first battery of the corresponding mobile device, thus reducing thevoltage drop of each mobile charging circuit; step S222: in afast-charging power supply mode, determining the level of the supplyvoltage according to the greatest one of the supply voltagescorresponding to the at least one mode inflection point, so as to chargethe first battery of the corresponding mobile device, thus enhancingcharging speed and reducing the voltage drop of each mobile chargingcircuit; or step S223: in a balance power supply mode, adjusting thelevel of the supply voltage, so that the adjusted level of the supplyvoltage lies between the greatest one of the supply voltagescorresponding to the at least one mode inflection point and the smallestone of the supply voltages corresponding to the at least one modeinflection point, thus charging the first battery of the correspondingmobile device, thereby balancing charging speed and power loss.

In one embodiment, subsequent to the step S22, the conversion controlcircuit is configured to operably control the switching power converterfurther according to the following step: step S4: in a case when sensingthe supply current and determining that the supply current has beendecreased by a preset current difference, adjusting the level of thesupply voltage up by a preset voltage difference, to continue chargingthe first battery of the corresponding mobile device, and repeating thisstep until the charging to the first batteries is terminated.

In one embodiment, subsequent to the step S22, the conversion controlcircuit is configured to operably control the switching power converterfurther according to the following step: step S5: after a presetcharging period has passed, proceeding back to the step S1.

In one embodiment, subsequent to the step S3, the conversion controlcircuit is configured to operably control the switching power converterfurther according to the following step: step S4: in a case when sensingthe supply current and determining that the supply current has beendecreased by a preset current difference, adjusting the level of thesupply voltage up by a preset voltage difference, to continue chargingthe first battery of the corresponding mobile device, and repeating thisstep until the charging to the first batteries is terminated.

In one embodiment, subsequent to the step S3, the conversion controlcircuit is configured to operably control the switching power converterfurther according to the following step: step S5: after a presetcharging period has passed, proceeding back to the step S1, andrepeating the steps S1-S3 and S5 until the charging to the firstbatteries is terminated.

In one embodiment, the charging control apparatus further comprises: astate of charge meter coupled to the conversion control circuit and asecond battery configured to operably provide an input power, whereinthe state of charge meter is configured to operably sense a current ofthe second battery during charging/discharging of the second battery, soas to record charge quantities of the second battery, wherein in asituation where the second battery is configured to operably provide thesupply power to the first mobile device and the second mobile device,the current of the second battery is substantially equal to the supplycurrent.

In one embodiment, the charging control apparatus further comprises thesecond battery.

In one embodiment, when the step S1 is being executed, the secondbattery ceases being charged.

In one embodiment, the mobile charging circuit is configured as a linearcharging circuit.

In one embodiment, in a case wherein it is determined that the firstmobile device and the second mobile device are in the charging modecombination (0), the charging control apparatus ceases providing thesupply power.

From another perspective, the present invention provides a chargingcontrol method, which is configured to operably provide a supply powerto a first mobile device and a second mobile device, wherein each of thefirst and the second mobile device includes: a mobile charging circuitand a first battery, wherein each mobile charging circuit is configuredto operably convert the supply power to a charging power for chargingthe corresponding first battery, wherein the mobile charging circuit isoperable in at least two charging modes of a precharging (PC) mode, aconstant current (CC) charging mode and a constant voltage (CV) chargingmode, so as to charge the corresponding first battery; the chargingcontrol apparatus comprising: step S1: controlling the switching powerconverter to gradually adjust a level of the supply voltage within apreset voltage range and sense a level of the corresponding supplycurrent through, or, to gradually adjust the level of the supply currentwithin a preset current range and sense the level of the correspondingsupply voltage, thereby establishing a current versus voltagecharacteristic curve corresponding to the supply power; and step S2:performing one of the following step S21 or S22 according to whether thecurrent versus voltage characteristic curve has at least one modeinflection point and according to information indicated by the supplycurrent and/or the supply voltage corresponding to the at least one modeinflection point in a situation where the at least one mode inflectionpoint is present: step S21: determining a charging mode combinationwhere the first mobile device and the second mobile device are in; orstep S22: in the situation where the at least one mode inflection pointis present, adjusting the supply voltage according to the informationindicated by the supply current and/or the supply voltage correspondingto the at least one mode inflection point, so as to charge the firstbattery of the corresponding mobile device according to the supplyvoltage, such that a voltage drop of each mobile charging circuit isreduced.

From yet another perspective, the present invention provides a chargingsystem, comprising: a plurality of mobile devices, which include a firstmobile device and a second mobile device, wherein each of the pluralityof mobile devices includes: a mobile charging circuit; a first battery,wherein each mobile charging circuit is configured to operably convert asupply power to a charging power for charging the corresponding firstbattery, wherein the mobile charging circuit is operable in at least twocharging modes of a precharging (PC) mode, a constant current (CC)charging mode and a constant voltage (CV) charging mode, so as to chargethe corresponding first battery; and a charging control apparatus, whichis coupled to the plurality of mobile devices in a removable way,wherein the charging control apparatus is configured to operably providethe supply power to the first mobile device and the second mobiledevice, wherein the charging control apparatus includes: a switchingpower converter, which is configured to operably convert an input powerto the supply power, wherein the supply power has a supply voltage and asupply current; and a conversion control circuit, which is configured tooperably control the switching power converter; wherein the conversioncontrol circuit is configured to operably control the switching powerconverter according to the following steps: step S1: controlling theswitching power converter to gradually adjust a level of the supplyvoltage within a preset voltage range and sense a level of thecorresponding supply current through, or, to gradually adjust the levelof the supply current within a preset current range and sense the levelof the corresponding supply voltage, thereby establishing a currentversus voltage characteristic curve corresponding to the supply power;and step S2: performing one of the following step S21 or S22 accordingto whether the current versus voltage characteristic curve has at leastone mode inflection point and according to information indicated by thesupply current and/or the supply voltage corresponding to the at leastone mode inflection point in a situation where the at least one modeinflection point is present: step S21: determining a charging modecombination where the first mobile device and the second mobile deviceare in; or step S22: in the situation where the at least one modeinflection point is present, adjusting the supply voltage according tothe information indicated by the supply current and/or the supplyvoltage corresponding to the at least one mode inflection point, so asto charge the first battery of the corresponding mobile device accordingto the supply voltage, such that a voltage drop of each mobile chargingcircuit is reduced.

The objectives, technical details, features, and effects of the presentinvention will be better understood with regard to the detaileddescription of the embodiments below, with reference to the attacheddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic block diagram of a conventional chargingcontrol apparatus for use in a mobile device.

FIG. 2 shows a schematic block diagram of a charging control apparatusfor use in a charging system according to an embodiment of the presentinvention.

FIG. 3 shows a schematic block diagram of a charging control apparatusfor use in a charging system according to another embodiment of thepresent invention.

FIG. 4 shows an embodiment of a current versus voltage characteristiccurve which is indicative of a mobile charging circuit charging abattery.

FIG. 5A to FIG. 5C show several embodiments of characteristic curves ofsupply current IS versus supply voltage VS which are indicative of amobile charging circuit charging different batteries in several chargingmodes, respectively.

FIG. 6A, FIG. 7A, FIG. 8A, FIG. 9A and FIG. 10A show several embodimentsof current versus voltage characteristic curves of a supply power indifferent cases wherein the two mobile devices are each in a same ordifferent charging mode.

FIG. 6B, FIG. 7B, FIG. 8B, FIG. 9B and FIG. 10B show several embodimentsof current versus voltage characteristic curves of a supply power, whichare indicative of different cases wherein the supply power issimultaneously provided to two mobile devices in correspondence to FIG.6A, FIG. 7A, FIG. 8A, FIG. 9A and FIG. 10A, respectively.

FIG. 11 shows a table that is a general list of mode inflection pointsversus various charging modes in which the two mobile devices operate.

FIG. 12A to FIG. 12C show flowcharts illustrating several embodiments ofhow a charging control apparatus controls a switching power converter.

FIG. 13 illustrates a current waveform diagram depicting the operationof a charging control apparatus of the present invention.

FIG. 14A shows a flowchart illustrating a further specific embodiment ofhow a conversion control circuit controls a switching power converter.

FIG. 14B shows a flowchart illustrating a further specific embodiment ofhow a conversion control circuit controls a switching power converter.

FIG. 14C shows a flowchart illustrating a specific embodiment of how aconversion control circuit controls a switching power converter.

FIG. 15 shows a flowchart illustrating a specific embodiment of how acharging control apparatus controls a switching power converter, so asto charge a mobile device.

FIG. 16A and FIG. 16B respectively show flowcharts illustrating twospecific embodiments of how a charging control apparatus controls aswitching power converter, so as to charge a mobile device.

FIG. 17 shows a flowchart a further specific embodiment of illustratinghow a charging control apparatus controls a switching power converter,so as to charge a mobile device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The drawings as referred to throughout the description of the presentinvention are for illustration only, to show the interrelations betweenthe circuits and the signal waveforms, but not drawn according to actualscale of circuit sizes and signal amplitudes and frequencies.

Please refer to FIG. 2, which shows a schematic block diagram of acharging control apparatus (i.e., charging control apparatus 102) foruse in a charging system (i.e., charging system 1002) according to anembodiment of the present invention. In one embodiment, the chargingcontrol apparatus 102 can be for example a charging box. The mobiledevices 50[1] and 50[2] can be for example true wireless stereo (TWS)headphones. In one embodiment, the charging control apparatus 102includes: a conversion control circuit 16 and a switching powerconverter 14. Each of the mobile devices 50[1] and 50[2] includes: amobile charging circuit 51 and a battery 52.

In one embodiment, the switching power converter 14 can be implementedas for example a buck-boost switching power converter. The switchingpower converter 14 is configured to operably convert an input power Vinto the supply power (which includes a supply voltage VS and a supplycurrent IS). The conversion control circuit 16 is configured to operablycontrol the switching power converter 14. The mobile charging circuit 51of each of the mobile devices 50[1] and 50[2] can convert the supplypower to a corresponding charging power (which includes a chargingvoltage Vch and a charging current Ich), to charge the correspondingbattery 52.

In one embodiment, the switching power converter 14 can be implementedas for example a buck-boost switching power converter, a buck switchingpower converter, a boost switching power converter or any other type ofswitching power converter. In one embodiment, the mobile chargingcircuit 51 can be implemented as for example a linear type chargingcircuit, which is only an illustrative example, but not for limiting thescope of the present invention. In other embodiments, the mobilecharging circuit 51 can be implemented as for example a switching typecharging circuit. In a case wherein the mobile charging circuit 51 isimplemented as a linear type charging circuit, the power loss of themobile device is positively correlated with a voltage drop across themobile charging circuit 51. Under such circumstance, the presentinvention is particularly advantageous.

Please refer to FIG. 3 which shows a schematic block diagram of acharging control apparatus (i.e., charging control apparatus 103) foruse in a charging system (i.e., charging system 1003) according toanother embodiment of the present invention. The charging controlapparatus 103 of this embodiment shown in FIG. 3 is similar to thecharging control apparatus 102 of the embodiment shown in FIG. 2, but isdifferent in that: the charging control apparatus 103 of this embodimentfurther includes a state of charge meter circuit 12. In this embodiment,the battery 11 supplies the above-mentioned input power Vin to aswitching power converter 14, and the battery 11 can be charged by anexternal power. The state of charge meter circuit 12 is coupled betweenthe battery 11 and the conversion control circuit 16. when the chargingcontrol apparatus 103 controls the battery 11 to be charged ordischarged, the state of charge meter circuit 12 is configured tooperably sense a current of the battery 11 via for example a sensingresistor Rcs, so as to record the charge quantity of the battery 11. Ina case wherein a supply power is supplied to the mobile devices 50[1]and 50[2] while in the meantime the battery 11 is not being charged, thecurrent flowing from the battery 11 corresponds to a supply current IS.In other words, when establishing a current versus voltagecharacteristic curve corresponding of the supply power, the chargingcontrol apparatus 103 can measure and obtain the supply current IS viathe state of charge meter circuit 12.

In one embodiment, the above-mentioned charging control apparatus 102shown in FIG. 2 or the above-mentioned charging control apparatus 103shown in FIG. 3 can be integrated into an integrated circuit (IC),excluding the battery 11.

Please still refer to FIG. 3. In one embodiment, the charging controlapparatus 103 can further comprise the above-mentioned battery 11. Undersuch circumstance, the charging control apparatus 103 can be, forexample, a charging box having a rechargeable battery 11.

Please refer to FIG. 4, which shows an embodiment of a current versusvoltage characteristic curve which is indicative of a mobile chargingcircuit charging a battery. In one embodiment, the mobile chargingcircuit 51 of the mobile device (i.e., 50[1] and 50[2]) is operable inat least two of the following charging modes: a precharging (PC) mode, aconstant current (CC) charging mode and a constant voltage (CV) chargingmode, to charge the battery 52.

The mobile charging circuit 51 can decide which charging mode is to beadopted according to a status of the battery 52. As shown in FIG. 4, inone embodiment, when a voltage of the battery 52 is greater than avoltage level V_PC and smaller than a voltage level V_CV, the mobilecharging circuit 51 will operate in a CC charging mode. Under suchcircumstance, the mobile charging circuit 51 will output for example aconstant charging current Ich having a current level of I_CC, to chargethe battery 52. When the voltage of the battery 52 reaches the voltagelevel V_CV, the mobile charging circuit 51 will operate in a CV chargingmode. Under such circumstance, the mobile charging circuit 51 willcharge the battery 52 by a constant charging voltage Vch having avoltage level of V_CV. When the voltage of the battery 52 is smallerthan the voltage level V_PC, the mobile charging circuit 51 will operatein a PC mode. Under such circumstance, the mobile charging circuit 51will output for example a constant charging current Ich having a currentlevel of I_PC, to charge the battery 52. Generally speaking, the currentlevel of I_PC current is smaller than the current level of I_CC. In oneembodiment, the current level of I_PC can be, for example but notlimited to, 1/10 of the current level of I_CC.

Please refer to FIG. 5A, which shows two embodiments of characteristiccurves of supply current IS versus supply voltage VS, indicative of amobile charging circuit charging different batteries having differentcharge quantities in the above-mentioned different charging modes. Asshown in FIG. 5A, in a case wherein the supply voltage VS isinadequately low, because the mobile charging circuit 51 is unable tooperate normally, the supply current IS is zero. On the other hand, in acase wherein the supply voltage VS is sufficiently high, the mobilecharging circuit 51 starts supplying the supply current IS to thebattery 52. Under such circumstance, the supply current IS increases asthe supply voltage VS increases. Subsequently, at a mode inflectionpoint of the characteristic curve, the mobile charging circuit 51 startscharging the battery 52 via a constant charging current Ich having acurrent level of I_PC. Under such circumstance, the current level of thesupply current IS is substantially equal to the current level of I_PC,and the supply current IS does not increase as the supply voltage VSincreases. It is noteworthy that, in one embodiment, when the mobilecharging circuit 51 operates in a PC mode, the supply voltage VScorresponding to the mode inflection point is relatively lower. FIG. 5Ais taken herein as an example, in this embodiment, in the PC mode, thesupply voltage VS[1] and the supply voltage VS[2] at their respectivemode inflection points are both approximately equal to 2.9V. The supplyvoltage VS[1] and the supply voltage VS[2] correspond to differentmobile charging circuits and/or different batteries, respectively.

Please refer to FIG. 5B, which show two embodiments of characteristiccurves of supply current IS versus supply voltage VS, indicative of amobile charging circuit charging different batteries having differentcharge quantities in a constant current (CC) charging mode. As shown inFIG. 5B, in a case wherein the supply voltage VS is inadequately low,because the mobile charging circuit 51 is unable to operate normally,the supply current IS is zero. On the other hand, in a case wherein thesupply voltage VS is sufficiently high, the mobile charging circuit 51starts supplying the supply current IS to the battery 52. Under suchcircumstance, the supply current IS increases as the supply voltage VSincreases. Subsequently, at a mode inflection point of thecharacteristic curve, the mobile charging circuit 51 starts charging thebattery 52 via a constant charging current Ich having a current level ofI_CC. Under such circumstance, the current level of the supply currentIS is substantially equal to the current level of I_CC, and the supplycurrent IS does not increase as the supply voltage VS increases. It isnoteworthy that, in one embodiment, when the mobile charging circuit 51operates in the CC mode, the supply voltage VS corresponding to the modeinflection point is higher than in the PC mode. FIG. 5B is taken hereinas an example. In this embodiment, in the CC mode, the mode inflectionpoints of the supply voltages (VS[1] and VS[2]) corresponding todifferent mobile charging circuits and/or different batteries bothexceed a CC voltage threshold Vthcc but does not exceed a CV voltagethreshold Vthcv. Besides, because the batteries have different chargequantities, the mode inflection point of the supply voltage VS[1] isdifferent from the mode inflection point of the supply voltage VS[2].However, the mode inflection points of the supply voltages VS[1] andVS[2] both lie between the CC voltage threshold Vthcc and the CV voltagethreshold Vthcv.

Please refer to FIG. 5C, which show two embodiments of characteristiccurves of supply current IS versus supply voltage VS, indicative of amobile charging circuit charging different batteries having differentcharge quantities in a constant voltage (CV) charging mode. As shown inFIG. 5C, in a case wherein the supply voltage VS is inadequately low,because the mobile charging circuit 51 is unable to operate normally,the supply current IS is zero. On the other hand, in a case wherein thesupply voltage VS is sufficiently high, the mobile charging circuit 51starts supplying the supply current IS to the battery 52. Under suchcircumstance, the supply current IS increases as the supply voltage VSincreases. Subsequently, at a mode inflection point of thecharacteristic curve, the mobile charging circuit 51 starts charging thebattery 52 via a charging current Ich having a current level which liesbetween a current level of I_PC and a current level of I_CC. Under suchcircumstance, the current level of the supply current IS issubstantially a constant during a short time period. And, the supplycurrent IS does not increase as the supply voltage VS increases. It isnoteworthy that, in one embodiment, when the mobile charging circuit 51operates in the CV mode, the supply voltage VS corresponding to the modeinflection point is relatively higher and is almost a constant fordifferent batteries. FIG. 5C is taken herein as an example. In thisembodiment, in the CV mode, the mode inflection points of the supplyvoltages (VS[1] and VS[2]) corresponding to different mobile chargingcircuits and/or different batteries both exceed the CV voltage thresholdVthcv. In this embodiment, in the CV mode, the supply voltage VS[1] andthe supply voltage VS[2] corresponding to the mode inflection points areboth approximately equal to 4.2V. Besides, because the batteries havedifferent charge quantities, the supply current IS[1] at the modeinflection point is different from the supply current IS[2] at the modeinflection point. However, the supply currents IS[1] and IS[2] at theirrespective mode inflection points both lie between the above-mentionedcurrent level of I_PC and the above-mentioned current level of I_CC.

It is noteworthy that, the above-mentioned characteristic curves shownin FIG. 5A to FIG. 5C are obtained by executing a short scan upondifferent mobile devices (including a corresponding mobile chargingcircuit and a corresponding battery), and the scan is completed during asufficiently short time period so as not to cause the charge quantitiesof the battery to change significantly. During measurements to obtainthe characteristic curves shown in FIG. 5A to FIG. 5C, one can measurethe supply current IS by controlling the supply voltage VS to vary, andcan measure the supply voltage VS by controlling the supply current ISto vary.

Note that the above-mentioned term “mode inflection point” is defined asa point where the current versus voltage characteristic curve transitsfrom a positive slop to zero, according to the coordinate system asshown in FIG. 5A to FIG. 5C.

In regard to a specific mobile device, the above-mentioned CC voltagethreshold Vthcc can be a determination voltage threshold whichdistinguishes a PC mode of this specific mobile device from a CC mode ofthis specific mobile device; the above-mentioned CV voltage thresholdVthcv can be a determination voltage threshold which distinguishes a CCmode of this specific mobile device from a CV mode of this specificmobile device.

FIG. 6A, FIG. 7A, FIG. 8A, FIG. 9A and FIG. 10A show several embodimentsof current versus voltage characteristic curves in different caseswherein two mobile devices (i.e., mobile device 50[1] and mobile device50[2]) are each in a same or different charging mode. FIG. 6B, FIG. 7B,FIG. 8B, FIG. 9B and FIG. 10B show several embodiments of current versusvoltage characteristic curves corresponding to a supply power, which areindicative of different cases wherein the supply power is simultaneouslyprovided to two mobile devices (i.e., mobile device 50[1] and mobiledevice 50[2]) in correspondence to FIG. 6A, FIG. 7A, FIG. 8A, FIG. 9Aand FIG. 10A, respectively.

In one embodiment, as shown in FIG. 6A, the mobile devices 50[1] and50[2] are both in the CC charging mode. When one supply power providespower to both the mobile devices 50[1] and 50[2], a correspondingcurrent versus voltage characteristic curve is as shown in FIG. 6B. Inone embodiment, the current versus voltage characteristic curve shown inFIG. 6B has two inflection points. The supply voltage VS and the supplycurrent IS corresponding to a first mode inflection point are 3.5V andI_CC, respectively. The supply voltage VS and the supply current IScorresponding to a second mode inflection point are 3.9V and 2*I_CC,respectively. In another embodiment, when the mobile devices 50[1] and50[2] are both in the CC charging mode, it is also possible that thecurrent versus voltage characteristic curve shown in FIG. 6B has onlyone inflection point. Under such situation, the inflection pointcorresponding to the mobile device 50[1] and the inflection pointcorresponding to the mobile device 50[2] coincide with each other.

In the embodiment shown in FIG. 7A and FIG. 7B, the mobile device 50[1]and the mobile device 50[2] are in the PC mode and the CC charging mode,respectively. In one embodiment, the current versus voltagecharacteristic curve shown in FIG. 7B has two inflection points. Thesupply voltage VS and the supply current IS corresponding to a firstmode inflection point are 2.9V and I_PC, respectively. The supplyvoltage VS and the supply current IS corresponding to a second modeinflection point are 3.9V and I_PC+I_CC, respectively.

In the embodiment shown in FIG. 8A and FIG. 8B, the mobile device 50[1]and the mobile device 50[2] are in the CC charging mode and the CVcharging mode, respectively. In one embodiment, the current versusvoltage characteristic curve shown in FIG. 8B has two inflection points.The supply voltage VS and the supply current IS corresponding to a firstmode inflection point are 3.9V and I_CC, respectively. The supplyvoltage VS and the supply current IS corresponding to a second modeinflection point are 4.2V and I_CC+I_CV, respectively. In oneembodiment, the current level of I_CV lies between the current level ofI_PC and the current level of I_CC.

In the embodiment shown in FIG. 9A and FIG. 9B, the mobile device 50[1]and the mobile device 50[2] are in the CC charging mode and a chargingtermination mode, respectively. In one embodiment, the current versusvoltage characteristic curve shown in FIG. 9B has one single inflectionpoint. The supply voltage VS and the supply current IS corresponding tothis one single mode inflection point are 3.9V and I_CC, respectively.

In the embodiment shown in FIG. 10A and FIG. 10B, the mobile device50[1] and the mobile device 50[2] are both in the charging terminationmode. In one embodiment, the current versus voltage characteristic curveshown in FIG. 10B does not have any inflection point. As shown in FIG.10B, within the voltage scanning range of the supply voltage VS, thesupply current IS remains as zero.

It is noteworthy that the voltage level of 2.9V in the above-mentionedpreferred embodiment is only an illustrative example, but not forlimiting the broadest scope of the present invention. The voltage levelof 2.9V corresponds to the above-mentioned voltage V_PC, which can bereferred to as a PC mode inflection point voltage, wherein the PC modeinflection point voltage V_PC is lower than the CC voltage thresholdVthcc. Besides, it is noteworthy that the voltage level of 4.2V in theabove-mentioned preferred embodiment is only an illustrative example,but not for limiting the broadest scope of the present invention. Thevoltage level of 4.2V corresponds to the above-mentioned voltage V_CV,which can be referred to as a CV charging mode inflection point voltage,wherein the CV charging mode inflection point voltage V_CV is higherthan the CV voltage threshold Vthcv. Moreover, it is noteworthy that thevoltage level of 3.9V in the above-mentioned preferred embodiment isonly an illustrative example, but not for limiting the broadest scope ofthe present invention. The voltage level of 3.9V corresponds to theabove-mentioned voltage V_CC, which can be referred to as a CC chargingmode inflection point voltage, wherein the CC charging mode inflectionpoint voltage V_CC lies between the CC voltage threshold Vthcc and theCV voltage threshold Vthcv.

It is required for the supply current IS to not only supply the chargingcurrent Ich, but also supply operation currents to circuits (e.g.,mobile charging circuit 51) inside the mobile devices 50[1] and 50[2],for these circuits to operate by. Therefore, it is noteworthy that theaforementioned current level of I_PC, I_CC, I_CV and zero of the supplycurrent IS are the net numbers wherein the operation currents have beendeducted.

From FIG. 6A to FIG. 10A, FIG. 6B to FIG. 10B and the correspondingdescription, it can be understood that: in a case wherein plural mobiledevices are supplied with the supply power simultaneously, a currentversus voltage characteristic curve corresponding to the supply power isactually a superposition of plural current versus voltage characteristiccurves of the cases by which each mobile device is individually suppliedwith the supply power. Given this feature, according to the presentinvention, the charging control apparatus can determine which chargingmode combination the plural mobile devices are in according to thefollowing: (1) whether any mode inflection point is present in thecurrent versus voltage characteristic curve; (2) the current level ofthe supply current IS corresponding to the mode inflection point in thecurrent versus voltage characteristic curve and/or (3) the voltage levelof the supply voltage VS corresponding to the mode inflection point inthe current versus voltage characteristic curve.

Please refer to FIG. 11, which shows a table that is a general list ofmode inflection points versus various charging modes in which the twomobile devices operate. It should be understood that the implementationsof the above-mentioned embodiments shown in FIG. 6A to FIG. 10A and FIG.6B to FIG. 10B are only an illustrative example, but not for limitingthe scope of the present invention.

As shown in FIG. 11, in a case wherein the charging control apparatus(e.g., charging control apparatus 102 shown in FIG. 2) provides a supplypower to two mobile devices (e.g., the mobile device 50[1] and themobile device 50[2] shown in FIG. 2), there are at least ten possiblemode combinations (i.e., mode combination (0) to mode combination (9))according to the relationship between the mode inflection point(s) inthe current versus voltage characteristic curve and the combinations ofthe charging modes.

The abbreviations in the table shown in FIG. 11 are explained below: inthe column of “charging mode combinations for the mobile device”: NCmeans not charging, denoting that the mobile device is in a chargingtermination mode; PC denotes that the mobile device is in a precharging(PC) mode; CC denotes that the mobile device is in a constant current(CC) charging mode; CV denotes that the mobile device is in a constantvoltage (CV) charging mode. The supply voltage VS and the supply currentIS corresponding to the first mode inflection point in the currentversus voltage characteristic curve of the supply power are denoted as“VS[1]” and “IS[1]”, respectively. The supply voltage VS and the supplycurrent IS corresponding to the second mode inflection point in thecurrent versus voltage characteristic curve of the supply power aredenoted as “VS[2]” and “IS[2]”, respectively. “none” denotes that thereis no mode inflection point in the current versus voltage characteristiccurve of the supply power, as illustrated by the mode combination (0).

In more detail, as shown in FIG. 11, in one embodiment, the chargingcontrol apparatus of the present invention can determine which chargingmode combination the two mobile devices 50[1] and 50[2] are in accordingto the following: (1) whether the first mode inflection point and/or thesecond mode inflection point is present in the current versus voltagecharacteristic curve of the supply power; and (2) when at least one modeinflection point is present, the current level or the current range ofthe supply current IS[1] and/or IS[2] at or subsequent to the modeinflection point. For example, in the mode combination (3), the supplycurrent IS[1] corresponding to the first mode inflection point has acurrent level of I_CC, while in the meantime, the second mode inflectionpoint is absent in the mode combination (3). For another example, in themode combination (5), the supply current IS[1] corresponding to thefirst mode inflection point has a current level of I_PC, whereas, thesupply current IS[1] corresponding to the second mode inflection pointhas a current level between the current level of 2*I_PC to the currentlevel of I_CC+I_PC. In one embodiment, the charging control apparatus ofthe present invention can determine which charging mode combination thetwo mobile devices 50[1] and 50[2] are in further according to thevoltage level or the voltage range of the supply voltage VS[1] and/orVS[2] at the mode inflection point, if at least one mode inflectionpoint is present.

For example, in a charging mode combination wherein a PC mode isincluded (e.g., the mode combination (4)), the supply voltage VS[1]corresponding to the first mode inflection point is smaller than the CCvoltage threshold Vthcc. For another example, in the mode combination(8), the supply voltage VS[1] corresponding to the first mode inflectionpoint lies between the CC voltage threshold Vthcc and the CV voltagethreshold Vthcv, which corresponds to the CC charging mode, and also inthe mode combination (8), the supply voltage VS[2] corresponding to thesecond mode inflection point is greater than the CV voltage thresholdVthcv, which corresponds to the CV charging mode. The rest of the modecombinations can be are not redundantly explained here, since they areself-explanatory.

Please refer to FIG. 12A to FIG. 12B, which show flowcharts illustratingseveral embodiments of how a charging control apparatus controls aswitching power converter.

Firstly, in the step S1, a current versus voltage characteristic curvecorresponding to the supply power is established, wherein the supplypower is supplied to plural mobile devices (e.g., the mobile device50[1] and the mobile device 50[2]). In more detail, the current versusvoltage characteristic curve corresponding to the supply power can beestablished by controlling a switching power converter (e.g., switchingpower converter 14) to gradually adjust the level of the supply voltageVS within a preset voltage range and sense the level of thecorresponding supply current IS. Or alternatively, the current versusvoltage characteristic curve corresponding to the supply power can beestablished by controlling a switching power converter (e.g., switchingpower converter 14) to gradually adjust the level of the supply currentIS within a preset current range and sense the level of thecorresponding supply voltage VS.

As shown in FIG. 12A, next, this embodiment proceeds to the step S2, toselectively perform one of the step S21 and the step S22 according towhether the current versus voltage characteristic curve has at least onemode inflection point and according to information indicated by thesupply current IS and/or the supply voltage VS corresponding to the atleast one mode inflection point in a situation where at least one modeinflection point is present.

Step S21: determining which charging mode combination the mobile device50[1] and the mobile device 50[2] are in; or

Step S22: in the situation where at least one mode inflection point ispresent, adjusting the supply voltage VS according to the informationindicated by the supply current IS and/or the supply voltage VScorresponding to the at least one mode inflection point, so as to chargethe battery 52 of each corresponding mobile device (e.g., the mobiledevice 50[1] and the mobile device 50[2]), thus reducing a voltage dropof the mobile charging circuit 51, thereby reducing power loss.

Please refer to FIG. 12A in conjugation with FIG. 3. In animplementation wherein the charging control apparatus 103 includes abattery 11 and the charging control apparatus 103 can measure the supplycurrent IS via a state of charge meter circuit 12, when the chargingcontrol apparatus 103 establishes a current versus voltagecharacteristic curve according to the step S1 and when the chargingcontrol apparatus 103 measures the supply current IS via the state ofcharge meter circuit 12, the battery 11 in the charging controlapparatus 103 ceases being charged, so that the current measured by thestate of charge meter circuit 12 can accurately reflect the supplycurrent IS.

Please refer to FIG. 12B, which shows a flowchart illustrating anembodiment of how a charging control apparatus controls a switchingpower converter. This embodiment shown in FIG. 12B is similar to theembodiment shown in FIG. 12A, but is different in that: in thisembodiment, subsequent to the step S21, the conversion control circuit16 is configured to operably control the switching power converter 14according to the following steps:

Step S3: according to the charging mode combination the mobile device50[1] and the mobile device 50[2] are in and according to theinformation indicated by the supply current IS and/or the supply voltageVS corresponding to the at least one mode inflection point, thisembodiment adjusts the supply voltage VS, so as to charge the batteries52 of the mobile devices (i.e., 50[1] and 50[2]), thus reducing thevoltage drop of the mobile charging circuits 51, thereby reducing powerloss.

Please refer to FIG. 6B along with FIG. 12B and FIG. 13. FIG. 13illustrates a current waveform diagram depicting the operation of acharging control apparatus of the present invention. To be morespecific, FIG. 13 illustrates a current waveform diagram correspondingto the embodiments shown in FIG. 6B and FIG. 12B. In one embodiment, asshown in FIG. 12B, subsequent to the step S3, the conversion controlcircuit 16 further controls the switching power converter 14 accordingto the following steps:

Step S4: when sensing the supply current IS and determining that thesupply current IS has been decreased by a preset current differenceI_stp (i.e., the step S41), this embodiment adjusts the level of thesupply voltage VS up by a preset voltage difference V_stp, and continuescharging the batteries 52 of the mobile devices (i.e., 50[1] and 50[2])(i.e., the step S42), wherein the step S41 and the step S42 arerepeatedly performed until the charging operation is terminated (i.e.,the step S8 to the step S10).

FIG. 13 is taken herein as an example. In the step S3, the level of thesupply voltage VS is adjusted to e.g. 3.5V (as shown by the time pointT1 in FIG. 13, wherein the time point T1 corresponds to for example thefirst mode inflection point shown in FIG. 6B), to start charging thebatteries 52 of the mobile devices (i.e., 50[1] and 50[2]). At thismoment, the supply current IS has a current level of I_CC, and thecharge quantities and the voltage level of each batteries 52 of themobile devices (i.e., 50[1] and/or 50[2]) will increase by time,whereas, the current level of I_CC of the supply current IS(corresponding to the charging current Ich) will decrease by time. Thisis because the increase of the voltage levels of the batteries 52 of themobile devices (i.e., 50[1] and/or 50[2]) results in insufficientheadroom between the adjusted supply voltage VS (which has an initialvoltage level of 3.5V) and the mobile charging circuit 51. Therefore, inresponse to the occurrence of the above-mentioned phenomenon, in thisembodiment, in a case wherein the supply current IS has been decreasedby a preset current difference I_stp (e.g., I_stp=0.2*I_CC), theconversion control circuit 16 will control the switching power converter14 to adjust the level of the supply voltage VS up by a preset voltagedifference V_stp (corresponding to the step S4), to continue chargingthe batteries 52 of the mobile devices (i.e., 50[1] and 50[2]) thereby.As shown in FIG. 13, for example, the preset voltage difference V_stp is0.3V, and at the time point T2, the voltage level of the supply voltageVS is adjusted to 3.8V, to continue charging the batteries 52 of themobile devices (i.e., 50[1] and 50[2]) accordingly. Such adjustmentoperation is repeatedly performed until the voltage level of the supplyvoltage VS has reaches a voltage level upper limit (e.g., 4.4V,corresponding to the time point T4). As shown in FIG. 13, subsequent tothe time point T4, the mobile device (i.e., 50[1] and/or 50[2]) willoperate in the CV charging mode (e.g., corresponding to the step S9shown in FIG. 12B, wherein the step S9 is a final section of thecharging operation). Under such circumstance, the current level of thesupply current IS (corresponding to the charging current Ich) willdecrease by time. When the current level of the supply current IS hasbeen decreased to I_PC, the mobile devices (i.e., 50[1] and/or 50[2])will stop being charged, and the switching power converter 14 can chooseto cease providing the supply power to the mobile device (i.e., 50[1]and/or 50[2]), to save electric power.

It is noteworthy that, in the embodiment shown in FIG. 13, the supplyvoltage VS is initially set to 3.5V for a primary purpose ofpower-saving, to reduce the voltage drops of all the mobile chargingcircuits 51 as much as possible. On the other hand, in otherembodiments, the supply voltage VS for example can be initially set to3.9V corresponding to the second mode inflection point in FIG. 6B (asshown by “VS[2]=3.9V” in FIG. 6B). Under such circumstance, theoperation corresponds to a fast-charging power supply mode, which stillreduces the voltage drops of all the mobile charging circuits 51 but notas much as in the power saving power supply mode, while enhances thecharging speed to reduce the required charging time. The details of thedifferent power supply modes (e.g., the power-saving power supply modeand the fast-charging power supply mode) will be more thoroughlyexplained later.

It is noteworthy that, the above-mentioned preset current differenceI_stp or the above-mentioned preset voltage difference V_stp can be aconstant or a variable. The above-mentioned preset current differenceI_stp and the above-mentioned preset voltage difference V_stp can beadaptively adjusted according to for example a charging mode where themobile devices (e.g., 50[1] and/or 50[2]) are in.

Please refer to FIG. 12C, which shows a flowchart illustrating anembodiment of how a charging control apparatus controls a switchingpower converter. This embodiment shown in FIG. 12C is similar to theembodiment shown in FIG. 12B, but is different in that: in thisembodiment, as shown in FIG. 12C, subsequent to the step S3, theconversion control circuit 16 is configured to operably control theswitching power converter 14 further according to the following steps:

Step S5: after a preset charging period T_stp has passed, thisembodiment goes back to the step S1, and this operation is repeatedlyperformed until the charging operation is terminated (the step S8 andthe step S10). To elaborate in detail, subsequent to the step S21 andthe step S3 whereby the batteries 52 of the mobile devices 50[1] and/or50[2] have been charged by the adaptively adjusted supply voltage VS fora preset charging period T_stp), this embodiment goes back to the stepS1 and executes the step S1 once again, so as to update the currentversus voltage characteristic curve corresponding to the supply power,and thereafter the supply voltage VS is adjusted according to thisupdated current versus voltage characteristic curve; such operation isrepeatedly performed until the charging operation is terminated.

It is noteworthy that, the above-mentioned preset charging period T_stpcan be a constant or a variable. The above-mentioned preset chargingperiod T_stp can be adaptively adjusted according to for example acharging mode where the mobile devices (e.g., 50[1] and/or 50[2]) arein.

Please refer to FIG. 14A, which shows a further specific embodiment ofthe step S21 in a flowchart illustrating how a conversion controlcircuit controls a switching power converter. Please refer to FIG. 14Aalong with FIG. 11. In this embodiment, the step S21 includes: in thesituation where at least one mode inflection point is present, thisembodiment compares the information indicated by the supply current IScorresponding to the at least one mode inflection point with a presetprecharging (PC) current level I_PC and a preset constant current (CC)current level I_CC, so as to determine which charging mode combinationthe mobile device 50[1] and the mobile device 50[2] are in. To elaboratein detail, because a mobile device has a specific current level or aspecific current level range when the mobile device operates in aspecific charging mode, this embodiment can determine which chargingmode combination the mobile device 50[1] and the mobile device 50[2] arein, according to a current level of the supply current IS at orsubsequent to the mode inflection point, the details of which will bemore thoroughly explained later.

Please refer to FIG. 14B, which shows a further specific embodiment ofthe step S21 in a flowchart illustrating how a conversion controlcircuit controls a switching power converter. Please refer to FIG. 14Balong with FIG. 11. In this embodiment, the step S21 further includes:this embodiment can compare the information indicated by the supplyvoltage VS corresponding to the at least one mode inflection point ofthe current versus voltage characteristic curve with a constant voltage(CV) voltage threshold Vthcv and a constant current (CC) voltagethreshold Vthcc, so as to determine which charging mode combination themobile device 50[1] and the mobile device 50[2] are in. To elaborate indetail, because a mobile devices has a specific voltage level or aspecific voltage level range when the mobile device operates in aspecific charging mode, this embodiment can determine which chargingmode combination the mobile device 50[1] and the mobile device 50[2] arein, according to a voltage level of the supply voltage VS at orsubsequent to the mode inflection point, the details of which will bemore thoroughly explained later.

Please refer to FIG. 14C, which shows a flowchart illustrating aspecific embodiment of how a conversion control circuit controls aswitching power converter. Please refer to FIG. 14C along with FIG. 11.In the step 21 shown in FIG. 14C, according to a current versus voltagecharacteristic curve and a table of charging modes shown in FIG. 11, thecharging control apparatus of this embodiment can determine whichcharging mode combination the mobile device 50[1] and the mobile device50[2] are in according to at least one of following steps:

Step S210: in a case wherein the current versus voltage characteristiccurve has no mode inflection point or in a case wherein within thepreset voltage range, the corresponding levels of the supply current ISare all lower than the preset PC current level I_PC, it is determinedthat the mobile device 50[1] and the mobile device 50[2] are in thecharging mode combination (0), wherein in the charging mode combination(0), the mobile device 50[1] and the mobile device 50[2] are both in thecharging termination mode. And/or,

Step S211: in a case wherein the current versus voltage characteristiccurve has one and only one mode inflection point and in a case whereinafter the supply voltage VS has exceeded the mode inflection point, thecorresponding level of the supply current IS is equal to the preset PCcurrent level I_PC, it is determined that the mobile device 50[1] andthe mobile device 50[2] are in the charging mode combination (1),wherein in the charging mode combination (1), one of the mobile device50[1] and the mobile device 50[2] is in the PC mode, whereas, anotherone of the mobile device 50[1] and the mobile device 50[2] is in thecharging termination mode. And/or,

Step S212: in a case wherein the current versus voltage characteristiccurve has one and only one mode inflection point and in a case whereinafter the supply voltage VS has exceeded the mode inflection point, thecorresponding level of the supply current IS is greater than the presetPC current level I_PC and smaller than the preset CC current level I_CC,it is determined that the mobile device 50[1] and the mobile device50[2] are in the charging mode combination (2), wherein in the chargingmode combination (2), one of the mobile device 50[1] and the mobiledevice 50[2] is in the CV charging mode, whereas, another one of themobile device 50[1] and the mobile device 50[2] is in the chargingtermination mode. And/or,

Step S213: in a case wherein the current versus voltage characteristiccurve has one and only one mode inflection point and in a case whereinafter the supply voltage VS has exceeded the mode inflection point, thecorresponding level of the supply current IS is equal to the preset CCcurrent level I_CC, it is determined that the mobile device 50[1] andthe mobile device 50[2] are in the charging mode combination (3),wherein in the charging mode combination (3), one of the mobile device50[1] and the mobile device 50[2] is in the CC charging mode, whereas,another one of the mobile device 50[1] and the mobile device 50[2] is inthe charging termination mode. And/or,

Step S214: in a case wherein the current versus voltage characteristiccurve has at least one mode inflection point and in a case wherein thelevel of the supply current IS which corresponds to a greatest one ofthe supply voltages VS corresponding to the at least one mode inflectionpoint is equal to two-fold of the preset PC current level I_PC, it isdetermined that the mobile device 50[1] and the mobile device 50[2] arein the charging mode combination (4), wherein in the charging modecombination (4), the mobile device 50[1] and the mobile device 50[2] areboth in the PC mode. And/or,

Step S215: in a case wherein the current versus voltage characteristiccurve has plural inflection points and in a case wherein the level ofthe supply current IS which corresponds to the greatest one of thesupply voltages VS corresponding to the at least one mode inflectionpoint is greater than two-fold of the preset PC current level andsmaller than a sum of the preset CC current level I_CC plus the presetPC current level I_PC, it is determined that the mobile device 50[1] andthe mobile device 50[2] are in the charging mode combination (5),wherein in the charging mode combination (5), one of the mobile device50[1] and the mobile device 50[2] is in the CV charging mode, whereas,another one of the mobile device 50[1] and the mobile device 50[2] is inthe PC mode. And/or,

Step S216: in a case wherein the current versus voltage characteristiccurve has the at least one mode inflection point and in a case whereinthe level of the supply current IS which corresponds to the greatest oneof the supply voltages VS corresponding to the at least one modeinflection point is greater than two-fold of the preset PC current levelI_PC and smaller than two-fold of the preset CC current level I_CC, itis determined that the mobile device 50[1] and the mobile device 50[2]are in the charging mode combination (6), wherein in the charging modecombination (6), the mobile device 50[1] and the mobile device 50[2] areboth in the CV charging mode. And/or,

Step S217: in a case wherein the current versus voltage characteristiccurve has the at least one mode inflection point and in a case whereinthe level of the supply current IS which corresponds to the greatest oneof the supply voltages VS corresponding to the at least one modeinflection point is equal to the sum of the preset CC current level I_CCplus the preset PC current level I_PC, it is determined that the mobiledevice 50[1] and the mobile device 50[2] are in the charging modecombination (7), wherein in the charging mode combination (7), one ofthe mobile device 50[1] and the mobile device 50[2] is in the CCcharging mode, whereas, another one of the mobile device 50[1] and themobile device 50[2] is in the PC mode. And/or,

Step S218: in a case wherein the current versus voltage characteristiccurve has the at least one mode inflection point and in a case whereinthe level of the supply current IS which corresponds to the greatest oneof the supply voltages VS corresponding to the at least one modeinflection point is greater than the sum of the preset CC current levelI_CC plus the preset PC current level I_PC and smaller than two-fold ofthe preset CC current level I_CC, it is determined that the mobiledevice 50[1] and the mobile device 50[2] are in the charging modecombination (8), wherein in the charging mode combination (8), one ofthe mobile device 50[1] and the mobile device 50[2] is in the CCcharging mode, whereas, another one of the mobile device 50[1] and themobile device 50[2] is in the CV charging mode. And/or,

Step S219: in a case wherein the current versus voltage characteristiccurve has the at least one mode inflection point and in a case whereinthe level of the supply current IS which corresponds to the greatest oneof the supply voltages VS corresponding to the at least one modeinflection point is equal to two-fold of the preset CC current levelI_CC, it is determined that the mobile device 50[1] and the mobiledevice 50[2] are in the charging mode combination (9), wherein in thecharging mode combination (9), the mobile device 50[1] and the mobiledevice 50[2] are both in the CC charging mode.

It is noteworthy that, the above-mentioned term “two-fold of the presetCC current level I_CC” as described in the step S216, the step S218 andthe step S219 can be understood as a sum of all the preset CC currentlevels I_CC of the mobile device 50[1] and the mobile device 50[2]. Thepreset CC current levels I_CC of the mobile device 50[1] and the mobiledevice 50[2] can be the same as or different from one another. Besides,it is noteworthy that, the above-mentioned term “two-fold of the presetPC current level I_PC” as described in the step S214 and the step S216can be understood as a sum of all the preset PC current levels I_PC ofthe mobile device 50[1] and the mobile device 50[2]. The preset PCcurrent levels I_PC of the mobile device 50[1] and the mobile device50[2] can be the same as or different from one another.

Please still refer to FIG. 14C along with FIG. 11. In one embodiment,the step S212 further includes: only when the information indicated bythe supply voltage VS corresponding to the at least one mode inflectionpoint is greater than or equal to the CV voltage threshold Vthcv, it isthen determined that the mobile device 50[1] and the mobile device 50[2]are in the charging mode combination (2).

In one embodiment, the step S215 further includes: only when theinformation indicated by the greatest one of the supply voltages VScorresponding to the mode inflection points is greater than or equal tothe CV voltage threshold Vthcv and when the information indicated by thesmallest one of the supply voltages VS corresponding to the modeinflection points is smaller than the CC voltage threshold Vthcc, it isthen determined that the mobile device 50[1] and the mobile device 50[2]are in the charging mode combination (5).

In one embodiment, the step S216 further includes: only when theinformation indicated by the supply voltages VS corresponding to the atleast one mode inflection point are all greater than or equal to the CVvoltage threshold Vthcv, it is then determined that the mobile device50[1] and the mobile device 50[2] are in the charging mode combination(6).

In one embodiment, the step S218 further includes: the step S218 furtherincludes: only when the information indicated by the greatest one of thesupply voltages VS corresponding to the at least one mode inflectionpoint is greater than the CV voltage threshold Vthcv and when theinformation indicated by the smallest one of the supply voltages VScorresponding to the at least one mode inflection point is smaller thanthe CV voltage threshold Vthcv and is greater than or equal to the CCvoltage threshold Vthcc, it is then determined that the mobile device50[1] and the mobile device 50[2] are in the charging mode combination(8).

It is noteworthy that, in one embodiment, when the charging controlapparatus determines that the mobile devices are in the charging modecombination (0) (i.e., all the mobile devices are in the chargingtermination mode), the charging control apparatus can cease providingthe supply power to the mobile devices, to save electric power.

Please refer to FIG. 15, which shows a flowchart illustrating a specificembodiment of how a charging control apparatus controls a switchingpower converter, so as to charge a mobile device. Ina case wherein thestep S21 is present, according to the charging mode combination wherethe mobile device 50[1] and the mobile device 50[2] are in, theconversion control circuit 16 can control the switching power converter14 to adjust the supply voltage VS, so as to charge the batteries 52 ofthe mobile devices (i.e., 50[1] and 50[2]) by an optimum voltage, thusreducing the voltage drops of the mobile charging circuits 51, therebyreducing power loss.

To elaborate in more detail, as shown in FIG. 15, in one embodiment, thestep S3 includes one of the following steps:

Step S31: in a case wherein the mobile device 50[1] and the mobiledevice 50[2] are determined via the above-mentioned mode determinationstep 21 to be in the charging mode combination (1), the charging modecombination (2) or the charging mode combination (3) (i.e., in a casewherein the current versus voltage characteristic curve has one and onlyone mode inflection point), according to the supply voltage VScorresponding to the one and the only one mode inflection point, thisembodiment can determine an initial voltage level of the supply voltageVS, to provide supply power to plural mobile device (i.e., 50[1] and50[2]) to charge the batteries 52 of the mobile devices (i.e., 50[1] and50[2]) simultaneously, thus enhancing charging speed and reducing thevoltage drops of the mobile charging circuits 51, thereby reducing powerloss.

In one embodiment, in a case wherein the current versus voltagecharacteristic curve has plural mode inflection points, the chargingcontrol apparatus (i.e., charging control apparatus 102 and/or chargingcontrol apparatus 103) of the present invention can determine thedistribution and arrangement of the supply power according to a powersupply mode which is for example preset by a user or determinedaccording to the conditions of the entire system in concern. Toelaborate in more detail, as shown in FIG. 15, in one embodiment, thestep S3 includes one of the following steps:

Step S32: in a case wherein the mobile device 50[1] and the mobiledevice 50[2] are in the charging mode combination (4) to (9) (i.e., in acase wherein the current versus voltage characteristic curve has pluralmode inflection points), in a power-saving power supply mode, accordingto the smallest one of the supply voltages VS corresponding to the atleast one mode inflection point, this embodiment can determine the levelof the supply voltage VS to charge the batteries 52 of the mobiledevices (i.e., 50[1] and 50[2]), thus reducing the voltage drops of themobile charging circuits 51, thereby reducing power loss. Or,

Step S33: in a case wherein the mobile device 50[1] and the mobiledevice 50[2] are in the charging mode combination (4) to (9), in afast-charging power supply mode, according to the greatest one of thesupply voltages VS corresponding to the at least one mode inflectionpoint, this embodiment can determine the level of the supply voltage VSto charge the batteries 52 of the mobile devices (i.e., 50[1] and50[2]), thus enhancing charging speed and reducing the voltage drops ofthe mobile charging circuits 51, thereby reducing power loss. Or,

Step S34: in a case wherein the mobile device 50[1] and the mobiledevice 50[2] are in the charging mode combination (4) to (9), in abalance power supply mode, this embodiment can adjust the level of thesupply voltage VS, so that the adjusted level of the supply voltage VSlies between the greatest one of the supply voltages VS corresponding tothe at least one mode inflection point and the smallest one of thesupply voltages VS corresponding to the at least one mode inflectionpoint, thus charging the batteries 52 of the mobile devices (i.e., 50[1]and 50[2]), thereby balancing charging speed and power loss.

It is noteworthy that, in a case wherein the mobile device 50[1] and themobile device 50[2] are in the charging mode combination (4) to (9)(i.e., in a case wherein the current versus voltage characteristic curvehas plural mode inflection points), in one embodiment, the voltagelevels of the supply voltages VS corresponding to the plural modeinflection points are clearly different from one another, so it can beclearly determined that the current versus voltage characteristic curvehas plural mode inflection points. However, in other embodiments,although the current versus voltage characteristic curve has plural modeinflection points, the voltage levels of the supply voltages VScorresponding to the plural mode inflection points may overlap orcoincide with one another, and in this case it cannot not bestraightforwardly determined that the current versus voltagecharacteristic curve has plural mode inflection points according to theappearance of the current versus voltage characteristic curve. Althoughgiven this factual obstacle, as long as the mobile device 50[1] and themobile device 50[2] are in the charging mode combination (4) to (9), itcan be regarded as that the current versus voltage characteristic curvehas plural mode inflection points.

Besides, as shown in FIG. 15, in one embodiment, prior to the steps S31to S34, the step S3 can further includes: a step S30 a and a step S30 b.In the step S30 a, this embodiment can determine whether the currentversus voltage characteristic curve has at least one mode inflectionpoint. When this embodiment determines that the current versus voltagecharacteristic curve does not have any mode inflection point(corresponding to the charging mode combination (0)), the switchingpower converter 14 can for example cease providing the supply power tothe mobile devices (i.e., 50[1] and/or 50[2]) (corresponding to the stepS10, “End”). In the step S30 b, this embodiment can determine whetherthe current versus voltage characteristic curve has one and only onemode inflection point (corresponding to the charging mode combination(1) to (3)). When this embodiment determines that the current versusvoltage characteristic curve have more than one mode inflection point,this embodiment determines that the mobile devices (i.e., 50[1] and/or50[2]) are in the charging mode combination (4) to (9).

Please refer to FIG. 16A and FIG. 16B, which respectively showflowcharts illustrating two specific embodiments of how a chargingcontrol apparatus controls a switching power converter, so as to chargea mobile device. The embodiments shown in FIG. 16A and FIG. 16B aresimilar to the embodiments shown in FIG. 12A to FIG. 12C, but aredifferent in that: in these embodiments, the step S21 (i.e., a modedetermination step) in FIG. 12A to FIG. 12C are omitted from theembodiments shown in FIG. 16A and FIG. 16B. Thus, unlike the embodimentsshown in FIG. 12A to FIG. 12C, the embodiments shown in FIG. 16A andFIG. 16B directly execute the step S22 (in the absence of the step S21)to adjust the supply voltage VS according to whether the current versusvoltage characteristic curve has at least one mode inflection point andaccording to the information indicated by the supply current IS and/orthe supply voltage VS corresponding to the at least one mode inflectionpoint in a situation where the at least one mode inflection point ispresent. The thus adjusted supply voltage VS is adopted to charge thebatteries 52 of the mobile devices (i.e., 50[1] and 50[2]).

As shown in FIG. 16A and FIG. 16B, in these embodiments, subsequent tothe step S22, the conversion control circuit 16 is configured tooperably control the switching power converter 14 according to the stepS4 (as shown in FIG. 16A) or the step S5 (as shown in FIG. 16B). Thestep S4 shown in FIG. 16A and the step S5 shown in FIG. 16B operate inthe same way as the step S4 shown in FIG. 12B and the step S5 shown inFIG. 12C as previously described, so the details thereof are notredundantly repeated here.

Please refer to FIG. 17, which shows a flowchart illustrating a furtherspecific embodiment of how a charging control apparatus controls aswitching power converter, so as to charge a mobile device. In thesituation where at least one mode inflection point is present, theconversion control circuit 16 is configured to operably decide thesupply voltage VS according to the information indicated by the supplycurrent IS and/or the supply voltage VS corresponding to the at leastone mode inflection point, so that the thus decided supply voltage VScharges the batteries 52 of the mobile devices (i.e., 50[1] and 50[2]),thus reducing the voltage drop of the mobile charging circuit 51,thereby reducing power loss.

To elaborate in more detail, as shown in FIG. 17, in one embodiment, thestep S22 includes one of the following steps:

Step S221: in a power-saving power supply mode, this embodiment candetermine the level of the supply voltage VS according to the smallestone of the supply voltages VS corresponding to the at least one modeinflection point, so as to charge the batteries 52 of the mobile devices(i.e., 50[1] and 50[2]) accordingly, thus reducing the voltage drop ofthe mobile charging circuit 51, thereby reducing power loss.

Step S222: in a fast-charging power supply mode, this embodiment candetermine the level of the supply voltage VS according to the greatestone of the supply voltages VS corresponding to the at least one modeinflection point, so as to charge the batteries 52 of the mobile devices(i.e., 50[1] and 50[2]) accordingly, thus enhancing charging speed andreducing the voltage drop of the mobile charging circuit 51, therebyreducing power loss; or

Step S223: in a balance power supply mode, this embodiment can adjustthe level of the supply voltage VS, so that the adjusted level of thesupply voltage VS lies between the greatest one of the supply voltagesVS corresponding to the at least one mode inflection point and thesmallest one of the supply voltages VS corresponding to the at least onemode inflection point, and charge the batteries 52 of the mobile devices(i.e., 50[1] and 50[2]) by the supply voltage VS, thereby balancingcharging speed and power loss.

It is noteworthy that, in the step S221 to the step S223, in a casewherein the current versus voltage characteristic curve has one and onlyone mode inflection point or in a case wherein the corresponding supplyvoltages VS coincide with each other, “the greatest one” or “thesmallest one” is the only one voltage level of the supply voltages VS.

In one embodiment, as shown in FIG. 17, prior to the step S221 to thestep S223, in one embodiment, the step S22 can further include a stepS220. In the step S220, it is determined whether the current versusvoltage characteristic curve has at least one mode inflection point.When the step S220 determines that the current versus voltagecharacteristic curve has no mode inflection point (corresponding to thecharging mode combination (0)). Under such circumstance, the switchingpower converter 14 can for example cease providing the supply power(corresponding to the step S10 shown in FIG. 17, i.e., “End”).

The present invention has been described in considerable detail withreference to certain preferred embodiments thereof. It should beunderstood that the description is for illustrative purpose, not forlimiting the broadest scope of the present invention. An embodiment or aclaim of the present invention does not need to achieve all theobjectives or advantages of the present invention. The title andabstract are provided for assisting searches but not for limiting thescope of the present invention. Those skilled in this art can readilyconceive variations and modifications within the spirit of the presentinvention. For example, to perform an action “according to” a certainsignal as described in the context of the present invention is notlimited to performing an action strictly according to the signal itself,but can be performing an action according to a converted form or ascaled-up or down form of the signal, i.e., the signal can be processedby a voltage-to-current conversion, a current-to-voltage conversion,and/or a ratio conversion, etc. before an action is performed. Foranother example, it should be understood that the implementation of theabove-mentioned embodiments as having two mobile devices is only anillustrative example, but not for limiting the scope of the presentinvention. Within the teaching of the present invention, those skilledin this art can readily conceive that it is also practicable and withinthe scope of the present invention that three or more mobile devices canbe adopted. Under such implementation, there will be three or morecorresponding mode inflection points. Besides, note that plural mobiledevices can have different features. To be more specific, differentmobile devices can operate indifferent charging modes. Or, whenoperating in a precharging (PC) mode, a constant current (CC) chargingmode or a constant voltage (CV) charging mode, different mobile devicesmay have different corresponding current levels and voltage levelscorresponding to the above-mentioned different charging modes. As longas these preset information can be obtained in advance, the modedetermination and supply voltage determination according to the presentinvention can be performed to achieve the above-mentioned efficacy ofpower saving. It is not limited for each of the embodiments describedhereinbefore to be used alone; under the spirit of the presentinvention, two or more of the embodiments described hereinbefore can beused in combination. For example, two or more of the embodiments can beused together, or, a part of one embodiment can be used to replace acorresponding part of another embodiment. In view of the foregoing, thespirit of the present invention should cover all such and othermodifications and variations, which should be interpreted to fall withinthe scope of the following claims and their equivalents.

What is claimed is:
 1. A charging control apparatus, which is configuredto operably provide a supply power to at least a first mobile device anda second mobile device, wherein each of the first and the second mobiledevice includes: a mobile charging circuit and a first battery, whereineach mobile charging circuit is configured to operably convert thesupply power to a charging power for charging the corresponding firstbattery, wherein the mobile charging circuit is operable in at least twoof the following charging modes: a precharging (PC) mode, a constantcurrent (CC) charging mode and a constant voltage (CV) charging mode, soas to charge the corresponding first battery; the charging controlapparatus comprising: a switching power converter, which is configuredto operably convert an input power to the supply power, wherein thesupply power has a supply voltage and a supply current; and a conversioncontrol circuit, which is configured to operably control the switchingpower converter; wherein the conversion control circuit is configured tooperably control the switching power converter according to thefollowing steps: step S1: controlling the switching power converter togradually adjust a level of the supply voltage within a preset voltagerange and sense a level of the corresponding supply current through, or,to gradually adjust the level of the supply current within a presetcurrent range and sense the level of the corresponding supply voltage,thereby establishing a current versus voltage characteristic curvecorresponding to the supply power; and step S2: performing one of thefollowing step S21 or S22 according to whether the current versusvoltage characteristic curve has at least one mode inflection point andaccording to information indicated by the supply current and/or thesupply voltage corresponding to the at least one mode inflection pointin a situation where the at least one mode inflection point is present:step S21: determining a charging mode combination where the first mobiledevice and the second mobile device are in; or step S22: in thesituation where the at least one mode inflection point is present,adjusting the supply voltage according to the information indicated bythe supply current and/or the supply voltage corresponding to the atleast one mode inflection point, so as to charge the first battery ofthe corresponding mobile device according to the supply voltage, suchthat a voltage drop of each mobile charging circuit is reduced.
 2. Thecharging control apparatus of claim 1, wherein the step S21 includes: inthe situation where the at least one mode inflection point is present,comparing the information indicated by the supply current correspondingto the at least one mode inflection point with a preset precharging (PC)current level and a preset constant current (CC) current level, so as todetermine the charging mode combination where the first mobile deviceand the second mobile device are in.
 3. The charging control apparatusof claim 1, wherein the step S21 includes: comparing the informationindicated by the supply voltage corresponding to the at least one modeinflection point of the current versus voltage characteristic curve witha constant voltage (CV) voltage threshold and a CC voltage threshold, soas to determine the charging mode combination where the first mobiledevice and the second mobile device are in.
 4. The charging controlapparatus of claim 1, wherein in the step S21, the conversion controlcircuit is configured to operably determine which charging modecombination the first mobile device and the second mobile device are inaccording to the current versus voltage characteristic curve by at leastone of following steps: step S210: in a case wherein the current versusvoltage characteristic curve has no mode inflection point, or, in a casewherein within the preset voltage range, the corresponding levels of thesupply current are all lower than the preset PC current level,determining that the first mobile device and the second mobile deviceare in a charging mode combination (0), wherein in the charging modecombination (0), the first mobile device and the second mobile deviceare both in a charging termination mode; step S211: in a case whereinthe current versus voltage characteristic curve has one and only onemode inflection point and in a case wherein after the supply voltage hasexceeded the mode inflection point, the corresponding level of thesupply current is equal to the preset PC current level, determining thatthe first mobile device and the second mobile device are in a chargingmode combination (1), wherein in the charging mode combination (1), oneof the first mobile device and the second mobile device is in the PCmode, whereas, another one of the first mobile device and the secondmobile device is in the charging termination mode; step S212: in a casewherein the current versus voltage characteristic curve has one and onlyone mode inflection point and in a case wherein after the supply voltagehas exceeded the mode inflection point, the corresponding level of thesupply current is greater than the preset PC current level and smallerthan the preset CC current level, determining that the first mobiledevice and the second mobile device are in a charging mode combination(2), wherein in the charging mode combination (2), one of the firstmobile device and the second mobile device is in the CV charging mode,whereas, another one of the first mobile device and the second mobiledevice is in the charging termination mode; step S213: in a case whereinthe current versus voltage characteristic curve has one and only onemode inflection point and in a case wherein after the supply voltage hasexceeded the mode inflection point, the corresponding level of thesupply current is equal to the preset CC current level, determining thatthe first mobile device and the second mobile device are in a chargingmode combination (3), wherein in the charging mode combination (3), oneof the first mobile device and the second mobile device is in the CCcharging mode, whereas, another one of the first mobile device and thesecond mobile device is in the charging termination mode; step S214: ina case wherein the current versus voltage characteristic curve has atleast one mode inflection point and in a case wherein the correspondinglevel of the supply current which corresponds to a greatest one of thesupply voltages corresponding to the at least one mode inflection pointis equal to two-fold of the preset PC current level, determining thatthe first mobile device and the second mobile device are in a chargingmode combination (4), wherein in the charging mode combination (4), thefirst mobile device and the second mobile device are both in the PCmode; step S215: in a case wherein the current versus voltagecharacteristic curve has a plurality of inflection points and in a casewherein the corresponding level of the supply current which correspondsto the greatest one of the supply voltages corresponding to the at leastone mode inflection point is greater than two-fold of the preset PCcurrent level and smaller than a sum of the preset CC current level plusthe preset PC current level, determining that the first mobile deviceand the second mobile device are in a charging mode combination (5),wherein in the charging mode combination (5), one of the first mobiledevice and the second mobile device is in the CV charging mode, whereas,another one of the first mobile device and the second mobile device isin the PC mode; step S216: in a case wherein the current versus voltagecharacteristic curve has the at least one mode inflection point and in acase wherein the corresponding level of the supply current whichcorresponds to the greatest one of the supply voltages corresponding tothe at least one mode inflection point is greater than two-fold of thepreset PC current level and smaller than two-fold of the preset CCcurrent level, determining that the first mobile device and the secondmobile device are in a charging mode combination (6), wherein in thecharging mode combination (6), the first mobile device and the secondmobile device are both in the CV charging mode; step S217: in a casewherein the current versus voltage characteristic curve has the at leastone mode inflection point and in a case wherein the corresponding levelof the supply current which corresponds to the greatest one of thesupply voltages corresponding to the at least one mode inflection pointis equal to the sum of the preset CC current level plus the preset PCcurrent level, determining that the first mobile device and the secondmobile device are in a charging mode combination (7), wherein in thecharging mode combination (7), one of the first mobile device and thesecond mobile device is in the CC charging mode, whereas, another one ofthe first mobile device and the second mobile device is in the PC mode;step S218: in a case wherein the current versus voltage characteristiccurve has the at least one mode inflection point and in a case whereinthe corresponding level of the supply current which corresponds to thegreatest one of the supply voltages corresponding to the at least onemode inflection point is greater than the sum of the preset CC currentlevel plus the preset PC current level and smaller than two-fold of thepreset CC current level, determining that the first mobile device andthe second mobile device are in a charging mode combination (8), whereinin the charging mode combination (8), one of the first mobile device andthe second mobile device is in the CC charging mode, whereas, anotherone of the first mobile device and the second mobile device is in the CVcharging mode; and/or step S219: in a case wherein the current versusvoltage characteristic curve has the at least one mode inflection pointand in a case wherein the corresponding level of the supply currentwhich corresponds to the greatest one of the supply voltagescorresponding to the at least one mode inflection point is equal totwo-fold of the preset CC current level, determining that the firstmobile device and the second mobile device are in a charging modecombination (9), wherein in the charging mode combination (9), the firstmobile device and the second mobile device are both in the CC chargingmode.
 5. The charging control apparatus of claim 4, wherein in a casewherein the charging control apparatus is configured to operablydetermine the charging mode combination where the first mobile deviceand the second mobile device are in according to at least one of thestep S212, the step S215, the step S216 or the step S218, each of thestep S212, the step S215, the step S216 and the step S218 furtherincludes a corresponding operation as the following: the step S212further including: only when the information indicated by the supplyvoltage corresponding to the at least one mode inflection point isgreater than or equal to the CV voltage threshold, then determining thatthe first mobile device and the second mobile device are in the chargingmode combination (2); the step S215 further including: only when theinformation indicated by the greatest one of the supply voltagescorresponding to the mode inflection points is greater than or equal tothe CV voltage threshold and when the information indicated by thesmallest one of the supply voltages corresponding to the mode inflectionpoints is smaller than the CC voltage threshold, then determining thatthe first mobile device and the second mobile device are in the chargingmode combination (5); the step S216 further including: only when theinformation indicated by the supply voltages corresponding to the atleast one mode inflection point are all greater than or equal to the CVvoltage threshold, then determining that the first mobile device and thesecond mobile device are in the charging mode combination (6); and/orthe step S218 further including: only when the information indicated bythe greatest one of the supply voltages corresponding to the at leastone mode inflection point is greater than the CV voltage threshold andwhen the information indicated by the smallest one of the supplyvoltages corresponding to the at least one mode inflection point issmaller than the CV voltage threshold and is greater than or equal tothe CC voltage threshold, then determining that the first mobile deviceand the second mobile device are in the charging mode combination (8).6. The charging control apparatus of claim 5, wherein in a case whereinthe step S21 is present, the conversion control circuit is configured tooperably control the switching power converter further according to thefollowing step: step S3: according to the charging mode combinationwhere the first mobile device and the second mobile device are in andaccording to the information indicated by the supply current and/or thesupply voltage corresponding to the at least one mode inflection point,adjusting the supply voltage to charge the first battery of thecorresponding mobile device, so as to reduce the voltage drop of eachmobile charging circuit.
 7. The charging control apparatus of claim 6,wherein the step S3 includes the following step: step S31: in a casewherein the first mobile device and the second mobile device are in thecharging mode combination (1), the charging mode combination (2) or thecharging mode combination (3), according to the supply voltagecorresponding to the one and the only one mode inflection point,determining the level of the supply voltage to charge the first batteryof the corresponding mobile device, so as to enhance charging speed andreduce the voltage drop of each mobile charging circuit.
 8. The chargingcontrol apparatus of claim 6, wherein the step S3 includes one of thefollowing steps: step S32: in a case wherein the first mobile device andthe second mobile device are in the charging mode combination (4) to(9), in a power-saving power supply mode, according to the smallest oneof the supply voltages corresponding to the at least one mode inflectionpoint, determining the level of the supply voltage to charge the firstbattery of the corresponding mobile device, thus reducing the voltagedrop of each mobile charging circuit; step S33: in a case wherein thefirst mobile device and the second mobile device are in the chargingmode combination (4) to (9), in a fast-charging power supply mode,according to the greatest one of the supply voltages corresponding tothe at least one mode inflection point, determining the level of thesupply voltage, so as to charge the first battery of the correspondingmobile device, thus enhancing charging speed and reducing the voltagedrop of each mobile charging circuit; or step S34: in a case wherein thefirst mobile device and the second mobile device are in the chargingmode combination (4) to (9), in a balance power supply mode, adjustingthe level of the supply voltage, so that the adjusted level of thesupply voltage lies between the greatest one of the supply voltagescorresponding to the at least one mode inflection point and the smallestone of the supply voltages corresponding to the at least one modeinflection point, thus charging the first battery of the correspondingmobile device, thereby balancing charging speed and power loss.
 9. Thecharging control apparatus of claim 1, wherein the step S22 includes oneof the following steps: step S221: in a power-saving power supply mode,determining the level of the supply voltage according to the smallestone of the supply voltages corresponding to the at least one modeinflection point, so as to charge the first battery of the correspondingmobile device, thus reducing the voltage drop of each mobile chargingcircuit; step S222: in a fast-charging power supply mode, determiningthe level of the supply voltage according to the greatest one of thesupply voltages corresponding to the at least one mode inflection point,so as to charge the first battery of the corresponding mobile device,thus enhancing charging speed and reducing the voltage drop of eachmobile charging circuit; or step S223: in a balance power supply mode,adjusting the level of the supply voltage, so that the adjusted level ofthe supply voltage lies between the greatest one of the supply voltagescorresponding to the at least one mode inflection point and the smallestone of the supply voltages corresponding to the at least one modeinflection point, thus charging the first battery of the correspondingmobile device, thereby balancing charging speed and power loss.
 10. Thecharging control apparatus of claim 1, wherein subsequent to the stepS22, the conversion control circuit is configured to operably controlthe switching power converter further according to the following step:step S4: in a case when sensing the supply current and determining thatthe supply current has been decreased by a preset current difference,adjusting the level of the supply voltage up by a preset voltagedifference, to continue charging the first battery of the correspondingmobile device, and repeating this step until the charging to the firstbatteries is terminated.
 11. The charging control apparatus of claim 1,wherein subsequent to the step S22, the conversion control circuit isconfigured to operably control the switching power converter furtheraccording to the following step: step S5: after a preset charging periodhas passed, proceeding back to the step S1.
 12. The charging controlapparatus of claim 6, wherein subsequent to the step S3, the conversioncontrol circuit is configured to operably control the switching powerconverter further according to the following step: step S4: in a casewhen sensing the supply current and determining that the supply currenthas been decreased by a preset current difference, adjusting the levelof the supply voltage up by a preset voltage difference, to continuecharging the first battery of the corresponding mobile device, andrepeating this step until the charging to the first batteries isterminated.
 13. The charging control apparatus of claim 6, whereinsubsequent to the step S3, the conversion control circuit is configuredto operably control the switching power converter further according tothe following step: step S5: after a preset charging period has passed,proceeding back to the step S1, and repeating the steps S1-S3 and S5until the charging to the first batteries is terminated.
 14. Thecharging control apparatus of claim 1, further comprising: a state ofcharge meter coupled to the conversion control circuit and a secondbattery configured to operably provide an input power, wherein the stateof charge meter is configured to operably sense a current of the secondbattery during charging/discharging of the second battery, so as torecord charge quantities of the second battery, wherein in a situationwhere the second battery is configured to operably provide the supplypower to the first mobile device and the second mobile device, thecurrent of the second battery is substantially equal to the supplycurrent.
 15. The charging control apparatus of claim 14, furthercomprising the second battery.
 16. The charging control apparatus ofclaim 14, wherein when the step S1 is being executed, the second batteryceases being charged.
 17. The charging control apparatus of claim 14,wherein the mobile charging circuit is configured as a linear chargingcircuit.
 18. The charging control apparatus of claim 14, wherein whendetermining that the first mobile device and the second mobile deviceare in the charging mode combination (0), the charging control apparatusceases providing the supply power.
 19. A charging control method, whichis configured to operably provide a supply power to a first mobiledevice and a second mobile device, wherein each of the first and thesecond mobile device includes: a mobile charging circuit and a firstbattery, wherein each mobile charging circuit is configured to operablyconvert the supply power to a charging power for charging thecorresponding first battery, wherein the mobile charging circuit isoperable in at least two charging modes of a precharging (PC) mode, aconstant current (CC) charging mode and a constant voltage (CV) chargingmode, so as to charge the corresponding first battery; the chargingcontrol apparatus comprising: step S1: controlling the switching powerconverter to gradually adjust a level of the supply voltage within apreset voltage range and sense a level of the corresponding supplycurrent through, or, to gradually adjust the level of the supply currentwithin a preset current range and sense the level of the correspondingsupply voltage, thereby establishing a current versus voltagecharacteristic curve corresponding to the supply power; and step S2:performing one of the following step S21 or S22 according to whether thecurrent versus voltage characteristic curve has at least one modeinflection point and according to information indicated by the supplycurrent and/or the supply voltage corresponding to the at least one modeinflection point in a situation where the at least one mode inflectionpoint is present: step S21: determining a charging mode combinationwhere the first mobile device and the second mobile device are in; orstep S22: in the situation where the at least one mode inflection pointis present, adjusting the supply voltage according to the informationindicated by the supply current and/or the supply voltage correspondingto the at least one mode inflection point, so as to charge the firstbattery of the corresponding mobile device according to the supplyvoltage, such that a voltage drop of each mobile charging circuit isreduced.
 20. The charging control method of claim 19, wherein the stepS21 includes: in the situation where the at least one mode inflectionpoint is present, comparing the information indicated by the supplycurrent corresponding to the at least one mode inflection point with apreset precharging (PC) current level and a preset constant current (CC)current level, so as to determine the charging mode combination wherethe first mobile device and the second mobile device are in.
 21. Thecharging control method of claim 19, wherein the step S21 includes:comparing the information indicated by the supply voltage correspondingto the at least one mode inflection point of the current versus voltagecharacteristic curve with a constant voltage (CV) voltage threshold anda CC voltage threshold, so as to determine the charging mode combinationwhere the first mobile device and the second mobile device are in. 22.The charging control method of claim 19, wherein the step S21 ofdetermining the charging mode combination where the first mobile deviceand the second mobile device are in according to the current versusvoltage characteristic curve includes at least one of following steps:step S210: in a case wherein the current versus voltage characteristiccurve has no mode inflection point, or, in a case wherein within thepreset voltage range, the corresponding levels of the supply current areall lower than the preset PC current level, determining that the firstmobile device and the second mobile device are in a charging modecombination (0), wherein in the charging mode combination (0), the firstmobile device and the second mobile device are both in a chargingtermination mode; step S211: in a case wherein the current versusvoltage characteristic curve has one and only one mode inflection pointand in a case wherein after the supply voltage has exceeded the modeinflection point, the corresponding level of the supply current is equalto the preset PC current level, determining that the first mobile deviceand the second mobile device are in a charging mode combination (1),wherein in the charging mode combination (1), one of the first mobiledevice and the second mobile device is in the PC mode, whereas, anotherone of the first mobile device and the second mobile device is in thecharging termination mode; step S212: in a case wherein the currentversus voltage characteristic curve has one and only one mode inflectionpoint and in a case wherein after the supply voltage has exceeded themode inflection point, the corresponding level of the supply current isgreater than the preset PC current level and smaller than the preset CCcurrent level, determining that the first mobile device and the secondmobile device are in a charging mode combination (2), wherein in thecharging mode combination (2), one of the first mobile device and thesecond mobile device is in the CV charging mode, whereas, another one ofthe first mobile device and the second mobile device is in the chargingtermination mode; step S213: in a case wherein the current versusvoltage characteristic curve has one and only one mode inflection pointand in a case wherein after the supply voltage has exceeded the modeinflection point, the corresponding level of the supply current is equalto the preset CC current level, determining that the first mobile deviceand the second mobile device are in a charging mode combination (3),wherein in the charging mode combination (3), one of the first mobiledevice and the second mobile device is in the CC charging mode, whereas,another one of the first mobile device and the second mobile device isin the charging termination mode; step S214: in a case wherein thecurrent versus voltage characteristic curve has at least one modeinflection point and in a case wherein the corresponding level of thesupply current which corresponds to a greatest one of the supplyvoltages corresponding to the at least one mode inflection point isequal to two-fold of the preset PC current level, determining that thefirst mobile device and the second mobile device are in a charging modecombination (4), wherein in the charging mode combination (4), the firstmobile device and the second mobile device are both in the PC mode; stepS215: in a case wherein the current versus voltage characteristic curvehas a plurality of inflection points and in a case wherein thecorresponding level of the supply current which corresponds to thegreatest one of the supply voltages corresponding to the at least onemode inflection point is greater than two-fold of the preset PC currentlevel and smaller than a sum of the preset CC current level plus thepreset PC current level, determining that the first mobile device andthe second mobile device are in a charging mode combination (5), whereinin the charging mode combination (5), one of the first mobile device andthe second mobile device is in the CV charging mode, whereas, anotherone of the first mobile device and the second mobile device is in the PCmode; step S216: in a case wherein the current versus voltagecharacteristic curve has the at least one mode inflection point and in acase wherein the corresponding level of the supply current whichcorresponds to the greatest one of the supply voltages corresponding tothe at least one mode inflection point is greater than two-fold of thepreset PC current level and smaller than two-fold of the preset CCcurrent level, determining that the first mobile device and the secondmobile device are in a charging mode combination (6), wherein in thecharging mode combination (6), the first mobile device and the secondmobile device are both in the CV charging mode; step S217: in a casewherein the current versus voltage characteristic curve has the at leastone mode inflection point and in a case wherein the corresponding levelof the supply current which corresponds to the greatest one of thesupply voltages corresponding to the at least one mode inflection pointis equal to the sum of the preset CC current level plus the preset PCcurrent level, determining that the first mobile device and the secondmobile device are in a charging mode combination (7), wherein in thecharging mode combination (7), one of the first mobile device and thesecond mobile device is in the CC charging mode, whereas, another one ofthe first mobile device and the second mobile device is in the PC mode;step S218: in a case wherein the current versus voltage characteristiccurve has the at least one mode inflection point and in a case whereinthe corresponding level of the supply current which corresponds to thegreatest one of the supply voltages corresponding to the at least onemode inflection point is greater than the sum of the preset CC currentlevel plus the preset PC current level and smaller than two-fold of thepreset CC current level, determining that the first mobile device andthe second mobile device are in a charging mode combination (8), whereinin the charging mode combination (8), one of the first mobile device andthe second mobile device is in the CC charging mode, whereas, anotherone of the first mobile device and the second mobile device is in the CVcharging mode; and/or step S219: in a case wherein the current versusvoltage characteristic curve has the at least one mode inflection pointand in a case wherein the corresponding level of the supply currentwhich corresponds to the greatest one of the supply voltagescorresponding to the at least one mode inflection point is equal totwo-fold of the preset CC current level, determining that the firstmobile device and the second mobile device are in a charging modecombination (9), wherein in the charging mode combination (9), the firstmobile device and the second mobile device are both in the CC chargingmode.
 23. The charging control method of claim 22, wherein in a casewherein the charging control apparatus is configured to operablydetermine the charging mode combination where the first mobile deviceand the second mobile device are in according to at least one of thestep S212, the step S215, the step S216 or the step S218, each of thestep S212, the step S215, the step S216 and the step S218 furtherincludes a corresponding operation as the following: the step S212further including: only when the information indicated by the supplyvoltage corresponding to the at least one mode inflection point isgreater than or equal to the CV voltage threshold, then determining thatthe first mobile device and the second mobile device are in the chargingmode combination (2); the step S215 further including: only when theinformation indicated by the greatest one of the supply voltagescorresponding to the mode inflection points is greater than or equal tothe CV voltage threshold and when the information indicated by thesmallest one of the supply voltages corresponding to the mode inflectionpoints is smaller than the CC voltage threshold, then determining thatthe first mobile device and the second mobile device are in the chargingmode combination (5); the step S216 further including: only when theinformation indicated by the supply voltages corresponding to the atleast one mode inflection point are all greater than or equal to the CVvoltage threshold, then determining that the first mobile device and thesecond mobile device are in the charging mode combination (6); and/orthe step S218 further including: only when the information indicated bythe greatest one of the supply voltages corresponding to the at leastone mode inflection point is greater than the CV voltage threshold andwhen the information indicated by the smallest one of the supplyvoltages corresponding to the at least one mode inflection point issmaller than the CV voltage threshold and is greater than or equal tothe CC voltage threshold, then determining that the first mobile deviceand the second mobile device are in the charging mode combination (8).24. The charging control method of claim 23, wherein in a case whereinthe step S21 is present, the conversion control circuit is configured tooperably control the switching power converter further according to thefollowing step: step S3: according to the charging mode combinationwhere the first mobile device and the second mobile device are in andaccording to the information indicated by the supply current and/or thesupply voltage corresponding to the at least one mode inflection point,adjusting the supply voltage to charge the first battery of thecorresponding mobile device, so as to reduce the voltage drop of eachmobile charging circuit.
 25. The charging control method of claim 24,wherein the step S3 includes the following step: step S31: in a casewherein the first mobile device and the second mobile device are in thecharging mode combination (1), the charging mode combination (2) or thecharging mode combination (3), according to the supply voltagecorresponding to the one and the only one mode inflection point,determining the level of the supply voltage to charge the first batteryof the corresponding mobile device, so as to enhance charging speed andreduce the voltage drop of each mobile charging circuit.
 26. Thecharging control method of claim 24, wherein the step S3 includes one ofthe following steps: step S32: in a case wherein the first mobile deviceand the second mobile device are in the charging mode combination (4) to(9), in a power-saving power supply mode, according to the smallest oneof the supply voltages corresponding to the at least one mode inflectionpoint, determining the level of the supply voltage to charge the firstbattery of the corresponding mobile device, thus reducing the voltagedrop of each mobile charging circuit; step S33: in a case wherein thefirst mobile device and the second mobile device are in the chargingmode combination (4) to (9), in a fast-charging power supply mode,according to the greatest one of the supply voltages corresponding tothe at least one mode inflection point, determining the level of thesupply voltage, so as to charge the first battery of the correspondingmobile device, thus enhancing charging speed and reducing the voltagedrop of each mobile charging circuit; or step S34: in a case wherein thefirst mobile device and the second mobile device are in the chargingmode combination (4) to (9), in a balance power supply mode, adjustingthe level of the supply voltage, so that the adjusted level of thesupply voltage lies between the greatest one of the supply voltagescorresponding to the at least one mode inflection point and the smallestone of the supply voltages corresponding to the at least one modeinflection point, thus charging the first battery of the correspondingmobile device, thereby balancing charging speed and power loss.
 27. Thecharging control method of claim 19, wherein the step S22 includes oneof the following steps: step S221: in a power-saving power supply mode,determining the level of the supply voltage according to the smallestone of the supply voltages corresponding to the at least one modeinflection point, so as to charge the first battery of the correspondingmobile device, thus reducing the voltage drop of each mobile chargingcircuit; step S222: in a fast-charging power supply mode, determiningthe level of the supply voltage according to the greatest one of thesupply voltages corresponding to the at least one mode inflection point,so as to charge the first battery of the corresponding mobile device,thus enhancing charging speed and reducing the voltage drop of eachmobile charging circuit; or step S223: in a balance power supply mode,adjusting the level of the supply voltage, so that the adjusted level ofthe supply voltage lies between the greatest one of the supply voltagescorresponding to the at least one mode inflection point and the smallestone of the supply voltages corresponding to the at least one modeinflection point, thus charging the first battery of the correspondingmobile device, thereby balancing charging speed and power loss.
 28. Thecharging control method of claim 19, wherein subsequent to the step S22,the conversion control circuit is configured to operably control theswitching power converter further according to the following step: stepS4: in a case when sensing the supply current and determining that thesupply current has been decreased by a preset current difference,adjusting the level of the supply voltage up by a preset voltagedifference, to continue charging the first battery of the correspondingmobile device, and repeating this step until the charging to the firstbatteries is terminated.
 29. The charging control method of claim 19,wherein subsequent to the step S22, the charging control method isconfigured to operably control the switching power converter furtheraccording to the following step: step S5: after a preset charging periodhas passed, proceeding back to the step S1.
 30. The charging controlmethod of claim 24, wherein subsequent to the step S3, the chargingcontrol method is configured to operably control the switching powerconverter further according to the following step: step S4: in a casewhen sensing the supply current and determining that the supply currenthas been decreased by a preset current difference, adjusting the levelof the supply voltage up by a preset voltage difference, to continuecharging the first battery of the corresponding mobile device, andrepeating this step until the charging to the first batteries isterminated.
 31. The charging control method of claim 24, whereinsubsequent to the step S3, the charging control method is configured tooperably control the switching power converter further according to thefollowing step: step S5: after a preset charging period has passed,proceeding back to the step S1, and repeating the steps S1-S3 and S5until the charging to the first batteries is terminated.
 32. Thecharging control method of claim 22, wherein when determining in thecharging combination (0), ceasing providing the supply power.
 33. Acharging system, comprising: a plurality of mobile devices, whichinclude a first mobile device and a second mobile device, wherein eachof the plurality of mobile devices includes: a mobile charging circuit;a first battery, wherein each mobile charging circuit is configured tooperably convert a supply power to a charging power for charging thecorresponding first battery, wherein the mobile charging circuit isoperable in at least two charging modes of a precharging (PC) mode, aconstant current (CC) charging mode and a constant voltage (CV) chargingmode, so as to charge the corresponding first battery; and a chargingcontrol apparatus, which is coupled to the plurality of mobile devicesin a removable way, wherein the charging control apparatus is configuredto operably provide the supply power to the first mobile device and thesecond mobile device, wherein the charging control apparatus includes: aswitching power converter, which is configured to operably convert aninput power to the supply power, wherein the supply power has a supplyvoltage and a supply current; and a conversion control circuit, which isconfigured to operably control the switching power converter; whereinthe conversion control circuit is configured to operably control theswitching power converter according to the following steps: step S1:controlling the switching power converter to gradually adjust a level ofthe supply voltage within a preset voltage range and sense a level ofthe corresponding supply current through, or, to gradually adjust thelevel of the supply current within a preset current range and sense thelevel of the corresponding supply voltage, thereby establishing acurrent versus voltage characteristic curve corresponding to the supplypower; and step S2: performing one of the following step S21 or S22according to whether the current versus voltage characteristic curve hasat least one mode inflection point and according to informationindicated by the supply current and/or the supply voltage correspondingto the at least one mode inflection point in a situation where the atleast one mode inflection point is present: step S21: determining acharging mode combination where the first mobile device and the secondmobile device are in; or step S22: in the situation where the at leastone mode inflection point is present, adjusting the supply voltageaccording to the information indicated by the supply current and/or thesupply voltage corresponding to the at least one mode inflection point,so as to charge the first battery of the corresponding mobile deviceaccording to the supply voltage, such that a voltage drop of each mobilecharging circuit is reduced.
 34. The charging system of claim 33,wherein the step S21 includes: in the situation where the at least onemode inflection point is present, comparing the information indicated bythe supply current corresponding to the at least one mode inflectionpoint with a preset precharging (PC) current level and a preset constantcurrent (CC) current level, so as to determine the charging modecombination where the first mobile device and the second mobile deviceare in.
 35. The charging system of claim 33, wherein the step S21includes: comparing the information indicated by the supply voltagecorresponding to the at least one mode inflection point of the currentversus voltage characteristic curve with a constant voltage (CV) voltagethreshold and a CC voltage threshold, so as to determine the chargingmode combination where the first mobile device and the second mobiledevice are in.
 36. The charging system of claim 33, wherein in a casewherein the step S21 is present, the conversion control circuit isconfigured to operably control the switching power converter furtheraccording to the following step: step S3: according to the charging modecombination where the first mobile device and the second mobile deviceare in and according to the information indicated by the supply currentand/or the supply voltage corresponding to the at least one modeinflection point, adjusting the supply voltage to charge the firstbattery of the corresponding mobile device, so as to reduce the voltagedrop of each mobile charging circuit.